Shell - RS485 Bricklet

This is the description of the Shell API bindings for the RS485 Bricklet. General information and technical specifications for the RS485 Bricklet are summarized in its hardware description.

An installation guide for the Shell API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Loopback

Download (example-loopback.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

# For this example connect the RX+/- pins to TX+/- pins on the same Bricklet
# and configure the DIP switch on the Bricklet to full-duplex mode

uid=XYZ # Change XYZ to the UID of your RS485 Bricklet

# Enable full-duplex mode
tinkerforge call rs485-bricklet $uid set-rs485-configuration 115200 parity-none stopbits-1 wordlength-8 duplex-full

# Handle incoming read callbacks
tinkerforge dispatch rs485-bricklet $uid read &

# Enable read callback
tinkerforge call rs485-bricklet $uid enable-read-callback

# Write "test" string
tinkerforge call rs485-bricklet $uid write t,e,s,t

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

Modbus Slave

Download (example-modbus-slave.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this


uid=XYZ # Change XYZ to the UID of your RS485 Bricklet
export _tmp=$(mktemp)
echo 0 > ${_tmp}

# Register write single register request callback
tinkerforge dispatch rs485-bricklet $uid modbus-slave-write-single-register-request \
  --execute "echo 'Request ID = {request-id}'
             echo 'Register Address = {register-address}'
             echo 'Register Value = {register-value}'

             # Here we assume valid writable register address is 42
             if [ {register-address} != 42 ]; then
               echo 'Requested invalid register address'
               tinkerforge call rs485-bricklet $uid modbus-slave-report-exception {request-id} exception-code-illegal-data-address
             else
               echo 'Request OK'
               tinkerforge call rs485-bricklet $uid modbus-slave-answer-write-single-register-request {request-id}
             fi" &

# Set operating mode to Modbus RTU slave
tinkerforge call rs485-bricklet $uid set-mode mode-modbus-slave-rtu

# Modbus specific configuration:
# - slave address = 17
# - master request timeout = 0ms (unused in slave mode)
tinkerforge call rs485-bricklet $uid set-modbus-configuration 17 0

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

Modbus Master

Download (example-modbus-master.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your RS485 Bricklet

export _tmp=$(mktemp)

# Register write single register response callback
tinkerforge dispatch rs485-bricklet $uid modbus-master-write-single-register-response\
  --execute "export _expected-request-id=\$(cat \$_tmp)

             if [ {request-id} != \"\$_expected-request-id\" ]; then
               echo 'Unexpected request ID'
             else
               echo 'Request ID = {request-id}'
               echo 'Exception Code = {exception-code}'
             fi

             rm -rf $_tmp" &

# Set operating mode to Modbus RTU master
tinkerforge call rs485-bricklet $uid set-mode mode-modbus-master-rtu

# Modbus specific configuration:
# - slave address = 1 (unused in master mode)
# - master request timeout = 1000ms
tinkerforge call rs485-bricklet $uid set-modbus-configuration 1 1000

# Request single register write
tinkerforge call rs485-bricklet $uid modbus-master-write-single-register 17 42 65535\
  --execute "echo {request-id} > ${_tmp}"

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

API

Possible exit codes for all tinkerforge commands are:

  • 1: interrupted (ctrl+c)
  • 2: syntax error
  • 21: Python 2.5 or newer is required
  • 22: Python argparse module is missing
  • 23: socket error
  • 24: other exception
  • 25: invalid placeholder in format string
  • 26: authentication error
  • 201: timeout occurred
  • 209: invalid argument value
  • 210: function is not supported
  • 211: unknown error

Command Structure

The common options of the call and dispatch commands are documented here. The specific command structure is shown below.

tinkerforge call rs485-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the RS485 Bricklet. It can take several options:

  • --help shows help for the specific call command and exits
  • --list-functions shows a list of known functions of the RS485 Bricklet and exits
tinkerforge dispatch rs485-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the RS485 Bricklet. It can take several options:

  • --help shows help for the specific dispatch command and exits
  • --list-callbacks shows a list of known callbacks of the RS485 Bricklet and exits
tinkerforge call rs485-bricklet <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The <function> to be called can take different options depending of its kind. All functions can take the following options:

  • --help shows help for the specific function and exits

Getter functions can take the following options:

  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Setter functions can take the following options:

  • --expect-response requests response and waits for it

The --expect-response option for setter functions allows to detect timeouts and other error conditions calls of setters as well. The device will then send a response for this purpose. If this option is not given for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch rs485-bricklet <uid> <callback> [<option>..]
Parameters:
  • <uid> -- string
  • <callback> -- string

The <callback> to be dispatched can take several options:

  • --help shows help for the specific callback and exits
  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Basic Functions

tinkerforge call rs485-bricklet <uid> write-low-level <message-length> <message-chunk-offset> <message-chunk-data>
Parameters:
  • <message-length> -- int
  • <message-chunk-offset> -- int
  • <message-chunk-data> -- char,char,..57x..,char
Output:
  • message-chunk-written -- int

Writes characters to the RS485 interface. The characters can be binary data, ASCII or similar is not necessary.

The return value is the number of characters that were written.

See set-rs485-configuration for configuration possibilities regarding baudrate, parity and so on.

tinkerforge call rs485-bricklet <uid> read-low-level <length>
Parameters:
  • <length> -- int
Output:
  • message-length -- int
  • message-chunk-offset -- int
  • message-chunk-data -- char,char,..57x..,char

Returns up to length characters from receive buffer.

Instead of polling with this function, you can also use callbacks. But note that this function will return available data only when the read callback is disabled. See enable-read-callback and read callback.

tinkerforge call rs485-bricklet <uid> set-rs485-configuration <baudrate> <parity> <stopbits> <wordlength> <duplex>
Parameters:
  • <baudrate> -- int
  • <parity> -- int (has symbols)
  • <stopbits> -- int (has symbols)
  • <wordlength> -- int (has symbols)
  • <duplex> -- int (has symbols)
Output:

no output

Sets the configuration for the RS485 communication. Available options:

  • Baudrate between 100 and 2000000 baud.
  • Parity of none, odd or even.
  • Stopbits can be 1 or 2.
  • Word length of 5 to 8.
  • Half- or Full-Duplex.

The default is: 115200 baud, parity none, 1 stop bit, word length 8, half duplex.

The following symbols are available for this function:

  • parity-none = 0, for <parity>
  • parity-odd = 1, for <parity>
  • parity-even = 2, for <parity>
  • stopbits-1 = 1, for <stopbits>
  • stopbits-2 = 2, for <stopbits>
  • wordlength-5 = 5, for <wordlength>
  • wordlength-6 = 6, for <wordlength>
  • wordlength-7 = 7, for <wordlength>
  • wordlength-8 = 8, for <wordlength>
  • duplex-half = 0, for <duplex>
  • duplex-full = 1, for <duplex>
tinkerforge call rs485-bricklet <uid> get-rs485-configuration
Output:
  • baudrate -- int
  • parity -- int (has symbols)
  • stopbits -- int (has symbols)
  • wordlength -- int (has symbols)
  • duplex -- int (has symbols)

Returns the configuration as set by set-rs485-configuration.

The following symbols are available for this function:

  • parity-none = 0, for parity
  • parity-odd = 1, for parity
  • parity-even = 2, for parity
  • stopbits-1 = 1, for stopbits
  • stopbits-2 = 2, for stopbits
  • wordlength-5 = 5, for wordlength
  • wordlength-6 = 6, for wordlength
  • wordlength-7 = 7, for wordlength
  • wordlength-8 = 8, for wordlength
  • duplex-half = 0, for duplex
  • duplex-full = 1, for duplex
tinkerforge call rs485-bricklet <uid> set-modbus-configuration <slave-address> <master-request-timeout>
Parameters:
  • <slave-address> -- int
  • <master-request-timeout> -- int
Output:

no output

Sets the configuration for the RS485 Modbus communication. Available options:

  • Slave Address: Address to be used as the Modbus slave address in Modbus slave mode. Valid Modbus slave address range is 1 to 247.
  • Master Request Timeout: Specifies how long the master should wait for a response from a slave in milliseconds when in Modbus master mode.

The default is: Slave Address = 1 and Master Request Timeout = 1000 milliseconds (1 second).

tinkerforge call rs485-bricklet <uid> get-modbus-configuration
Output:
  • slave-address -- int
  • master-request-timeout -- int

Returns the configuration as set by set-modbus-configuration.

tinkerforge call rs485-bricklet <uid> set-mode <mode>
Parameters:
  • <mode> -- int (has symbols)
Output:

no output

Sets the mode of the Bricklet in which it operates. Available options are

  • RS485,
  • Modbus Master RTU and
  • Modbus Slave RTU.

The default is: RS485 mode.

The following symbols are available for this function:

  • mode-rs485 = 0, for <mode>
  • mode-modbus-master-rtu = 1, for <mode>
  • mode-modbus-slave-rtu = 2, for <mode>
tinkerforge call rs485-bricklet <uid> get-mode
Output:
  • mode -- int (has symbols)

Returns the configuration as set by set-mode.

The following symbols are available for this function:

  • mode-rs485 = 0, for mode
  • mode-modbus-master-rtu = 1, for mode
  • mode-modbus-slave-rtu = 2, for mode

Advanced Functions

tinkerforge call rs485-bricklet <uid> set-communication-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

Sets the communication LED configuration. By default the LED shows RS485 communication traffic by flickering.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is off.

The following symbols are available for this function:

  • communication-led-config-off = 0, for <config>
  • communication-led-config-on = 1, for <config>
  • communication-led-config-show-heartbeat = 2, for <config>
  • communication-led-config-show-communication = 3, for <config>
tinkerforge call rs485-bricklet <uid> get-communication-led-config
Output:
  • config -- int (has symbols)

Returns the configuration as set by set-communication-led-config

The following symbols are available for this function:

  • communication-led-config-off = 0, for config
  • communication-led-config-on = 1, for config
  • communication-led-config-show-heartbeat = 2, for config
  • communication-led-config-show-communication = 3, for config
tinkerforge call rs485-bricklet <uid> set-error-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

Sets the error LED configuration.

By default the error LED turns on if there is any error (see error-count callback). If you call this function with the SHOW ERROR option again, the LED will turn off until the next error occurs.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is off.

The following symbols are available for this function:

  • error-led-config-off = 0, for <config>
  • error-led-config-on = 1, for <config>
  • error-led-config-show-heartbeat = 2, for <config>
  • error-led-config-show-error = 3, for <config>
tinkerforge call rs485-bricklet <uid> get-error-led-config
Output:
  • config -- int (has symbols)

Returns the configuration as set by set-error-led-config.

The following symbols are available for this function:

  • error-led-config-off = 0, for config
  • error-led-config-on = 1, for config
  • error-led-config-show-heartbeat = 2, for config
  • error-led-config-show-error = 3, for config
tinkerforge call rs485-bricklet <uid> set-buffer-config <send-buffer-size> <receive-buffer-size>
Parameters:
  • <send-buffer-size> -- int
  • <receive-buffer-size> -- int
Output:

no output

Sets the send and receive buffer size in byte. In sum there is 10240 byte (10kb) buffer available and the minimum buffer size is 1024 byte (1kb) for both.

The current buffer content is lost if this function is called.

The send buffer holds data that was given by write and could not be written yet. The receive buffer holds data that is received through RS485 but could not yet be send to the user, either by read or through read callback.

The default configuration is 5120 byte (5kb) per buffer.

tinkerforge call rs485-bricklet <uid> get-buffer-config
Output:
  • send-buffer-size -- int
  • receive-buffer-size -- int

Returns the buffer configuration as set by set-buffer-config.

tinkerforge call rs485-bricklet <uid> get-buffer-status
Output:
  • send-buffer-used -- int
  • receive-buffer-used -- int

Returns the currently used bytes for the send and received buffer.

See set-buffer-config for buffer size configuration.

tinkerforge call rs485-bricklet <uid> get-error-count
Output:
  • overrun-error-count -- int
  • parity-error-count -- int

Returns the current number of overrun and parity errors.

tinkerforge call rs485-bricklet <uid> get-modbus-common-error-count
Output:
  • timeout-error-count -- int
  • checksum-error-count -- int
  • frame-too-big-error-count -- int
  • illegal-function-error-count -- int
  • illegal-data-address-error-count -- int
  • illegal-data-value-error-count -- int
  • slave-device-failure-error-count -- int

Returns the current number of errors occurred in Modbus mode.

  • Timeout Error Count: Number of timeouts occurred.
  • Checksum Error Count: Number of failures due to Modbus frame CRC16 checksum mismatch.
  • Frame Too Big Error Count: Number of times frames were rejected because they exceeded maximum Modbus frame size which is 256 bytes.
  • Illegal Function Error Count: Number of errors when an unimplemented or illegal function is requested. This corresponds to Modbus exception code 1.
  • Illegal Data Address Error Count: Number of errors due to invalid data address. This corresponds to Modbus exception code 2.
  • Illegal Data Value Error Count: Number of errors due to invalid data value. This corresponds to Modbus exception code 3.
  • Slave Device Failure Error Count: Number of errors occurred on the slave device which were unrecoverable. This corresponds to Modbus exception code 4.
tinkerforge call rs485-bricklet <uid> modbus-slave-report-exception <request-id> <exception-code>
Parameters:
  • <request-id> -- int
  • <exception-code> -- int (has symbols)
Output:

no output

In Modbus slave mode this function can be used to report a Modbus exception for a Modbus master request.

  • Request ID: Request ID of the request received by the slave.
  • Exception Code: Modbus exception code to report to the Modbus master.

The following symbols are available for this function:

  • exception-code-timeout = -1, for <exception-code>
  • exception-code-success = 0, for <exception-code>
  • exception-code-illegal-function = 1, for <exception-code>
  • exception-code-illegal-data-address = 2, for <exception-code>
  • exception-code-illegal-data-value = 3, for <exception-code>
  • exception-code-slave-device-failure = 4, for <exception-code>
  • exception-code-acknowledge = 5, for <exception-code>
  • exception-code-slave-device-busy = 6, for <exception-code>
  • exception-code-memory-parity-error = 8, for <exception-code>
  • exception-code-gateway-path-unavailable = 10, for <exception-code>
  • exception-code-gateway-target-device-failed-to-respond = 11, for <exception-code>
tinkerforge call rs485-bricklet <uid> modbus-slave-answer-read-coils-request-low-level <request-id> <coils-length> <coils-chunk-offset> <coils-chunk-data>
Parameters:
  • <request-id> -- int
  • <coils-length> -- int
  • <coils-chunk-offset> -- int
  • <coils-chunk-data> -- bool,bool,..469x..,bool
Output:

no output

In Modbus slave mode this function can be used to answer a master request to read coils.

  • Request ID: Request ID of the corresponding request that is being answered.
  • Coils: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the modbus-slave-read-coils-request callback with the Request ID as provided by the argument of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-read-coils <slave-address> <starting-address> <count>
Parameters:
  • <slave-address> -- int
  • <starting-address> -- int
  • <count> -- int
Output:
  • request-id -- int

In Modbus master mode this function can be used to read coils from a slave. This function creates a Modbus function code 1 request.

  • Slave Address: Address of the target Modbus slave.
  • Starting Address: Starting address of the read.
  • Count: Number of coils to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-read-coils-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-read-holding-registers-request-low-level <request-id> <holding-registers-length> <holding-registers-chunk-offset> <holding-registers-chunk-data>
Parameters:
  • <request-id> -- int
  • <holding-registers-length> -- int
  • <holding-registers-chunk-offset> -- int
  • <holding-registers-chunk-data> -- int,int,..26x..,int
Output:

no output

In Modbus slave mode this function can be used to answer a master request to read holding registers.

  • Request ID: Request ID of the corresponding request that is being answered.
  • Holding Registers: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the modbus-slave-read-holding-registers-request callback with the Request ID as provided by the argument of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-read-holding-registers <slave-address> <starting-address> <count>
Parameters:
  • <slave-address> -- int
  • <starting-address> -- int
  • <count> -- int
Output:
  • request-id -- int

In Modbus master mode this function can be used to read holding registers from a slave. This function creates a Modbus function code 3 request.

  • Slave Address: Address of the target Modbus slave.
  • Starting Address: Starting address of the read.
  • Count: Number of holding registers to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-read-holding-registers-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-write-single-coil-request <request-id>
Parameters:
  • <request-id> -- int
Output:

no output

In Modbus slave mode this function can be used to answer a master request to write a single coil.

  • Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the modbus-slave-write-single-coil-request callback with the Request ID as provided by the arguments of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-write-single-coil <slave-address> <coil-address> <coil-value>
Parameters:
  • <slave-address> -- int
  • <coil-address> -- int
  • <coil-value> -- bool
Output:
  • request-id -- int

In Modbus master mode this function can be used to write a single coil of a slave. This function creates a Modbus function code 5 request.

  • Slave Address: Address of the target Modbus slave.
  • Coil Address: Address of the coil.
  • Coil Value: Value to be written.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-write-single-coil-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-write-single-register-request <request-id>
Parameters:
  • <request-id> -- int
Output:

no output

In Modbus slave mode this function can be used to answer a master request to write a single register.

  • Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the modbus-slave-write-single-register-request callback with the Request ID, Register Address and Register Value as provided by the arguments of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-write-single-register <slave-address> <register-address> <register-value>
Parameters:
  • <slave-address> -- int
  • <register-address> -- int
  • <register-value> -- int
Output:
  • request-id -- int

In Modbus master mode this function can be used to write a single register of a slave. This function creates a Modbus function code 6 request.

  • Slave Address: Address of the target Modbus slave.
  • Register Address: Address of the register.
  • Register Value: Value to be written.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-write-single-register-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-write-multiple-coils-request <request-id>
Parameters:
  • <request-id> -- int
Output:

no output

In Modbus slave mode this function can be used to answer a master request to write multiple coils.

  • Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the modbus-slave-write-multiple-coils-request callback with the Request ID of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-write-multiple-coils-low-level <slave-address> <starting-address> <coils-length> <coils-chunk-offset> <coils-chunk-data>
Parameters:
  • <slave-address> -- int
  • <starting-address> -- int
  • <coils-length> -- int
  • <coils-chunk-offset> -- int
  • <coils-chunk-data> -- bool,bool,..437x..,bool
Output:
  • request-id -- int

In Modbus master mode this function can be used to write multiple coils of a slave. This function creates a Modbus function code 15 request.

  • Slave Address: Address of the target Modbus slave.
  • Starting Address: Starting address of the write.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-write-multiple-coils-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-write-multiple-registers-request <request-id>
Parameters:
  • <request-id> -- int
Output:

no output

In Modbus slave mode this function can be used to answer a master request to write multiple registers.

  • Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the modbus-slave-write-multiple-registers-request callback with the Request ID of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-write-multiple-registers-low-level <slave-address> <starting-address> <registers-length> <registers-chunk-offset> <registers-chunk-data>
Parameters:
  • <slave-address> -- int
  • <starting-address> -- int
  • <registers-length> -- int
  • <registers-chunk-offset> -- int
  • <registers-chunk-data> -- int,int,..24x..,int
Output:
  • request-id -- int

In Modbus master mode this function can be used to write multiple registers of a slave. This function creates a Modbus function code 16 request.

  • Slave Address: Address of the target Modbus slave.
  • Starting Address: Starting Address of the write.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-write-multiple-registers-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-read-discrete-inputs-request-low-level <request-id> <discrete-inputs-length> <discrete-inputs-chunk-offset> <discrete-inputs-chunk-data>
Parameters:
  • <request-id> -- int
  • <discrete-inputs-length> -- int
  • <discrete-inputs-chunk-offset> -- int
  • <discrete-inputs-chunk-data> -- bool,bool,..469x..,bool
Output:

no output

In Modbus slave mode this function can be used to answer a master request to read discrete inputs.

  • Request ID: Request ID of the corresponding request that is being answered.
  • Discrete Inputs: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the modbus-slave-read-discrete-inputs-request callback with the Request ID as provided by the argument of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-read-discrete-inputs <slave-address> <starting-address> <count>
Parameters:
  • <slave-address> -- int
  • <starting-address> -- int
  • <count> -- int
Output:
  • request-id -- int

In Modbus master mode this function can be used to read discrete inputs from a slave. This function creates a Modbus function code 2 request.

  • Slave Address: Address of the target Modbus slave.
  • Starting Address: Starting address of the read.
  • Count: Number of discrete inputs to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-read-discrete-inputs-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> modbus-slave-answer-read-input-registers-request-low-level <request-id> <input-registers-length> <input-registers-chunk-offset> <input-registers-chunk-data>
Parameters:
  • <request-id> -- int
  • <input-registers-length> -- int
  • <input-registers-chunk-offset> -- int
  • <input-registers-chunk-data> -- int,int,..26x..,int
Output:

no output

In Modbus slave mode this function can be used to answer a master request to read input registers.

  • Request ID: Request ID of the corresponding request that is being answered.
  • Input Registers: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the modbus-slave-read-input-registers-request callback with the Request ID as provided by the argument of the callback.

tinkerforge call rs485-bricklet <uid> modbus-master-read-input-registers <slave-address> <starting-address> <count>
Parameters:
  • <slave-address> -- int
  • <starting-address> -- int
  • <count> -- int
Output:
  • request-id -- int

In Modbus master mode this function can be used to read input registers from a slave. This function creates a Modbus function code 4 request.

  • Slave Address: Address of the target Modbus slave.
  • Starting Address: Starting address of the read.
  • Count: Number of input registers to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the modbus-master-read-input-registers-response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

tinkerforge call rs485-bricklet <uid> get-spitfp-error-count
Output:
  • error-count-ack-checksum -- int
  • error-count-message-checksum -- int
  • error-count-frame -- int
  • error-count-overflow -- int

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

tinkerforge call rs485-bricklet <uid> set-bootloader-mode <mode>
Parameters:
  • <mode> -- int (has symbols)
Output:
  • status -- int (has symbols)

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for <mode>
  • bootloader-mode-firmware = 1, for <mode>
  • bootloader-mode-bootloader-wait-for-reboot = 2, for <mode>
  • bootloader-mode-firmware-wait-for-reboot = 3, for <mode>
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for <mode>
  • bootloader-status-ok = 0, for status
  • bootloader-status-invalid-mode = 1, for status
  • bootloader-status-no-change = 2, for status
  • bootloader-status-entry-function-not-present = 3, for status
  • bootloader-status-device-identifier-incorrect = 4, for status
  • bootloader-status-crc-mismatch = 5, for status
tinkerforge call rs485-bricklet <uid> get-bootloader-mode
Output:
  • mode -- int (has symbols)

Returns the current bootloader mode, see set-bootloader-mode.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for mode
  • bootloader-mode-firmware = 1, for mode
  • bootloader-mode-bootloader-wait-for-reboot = 2, for mode
  • bootloader-mode-firmware-wait-for-reboot = 3, for mode
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for mode
tinkerforge call rs485-bricklet <uid> set-write-firmware-pointer <pointer>
Parameters:
  • <pointer> -- int
Output:

no output

Sets the firmware pointer for write-firmware. The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

tinkerforge call rs485-bricklet <uid> write-firmware <data>
Parameters:
  • <data> -- int,int,..61x..,int
Output:
  • status -- int

Writes 64 Bytes of firmware at the position as written by set-write-firmware-pointer before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

tinkerforge call rs485-bricklet <uid> set-status-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following symbols are available for this function:

  • status-led-config-off = 0, for <config>
  • status-led-config-on = 1, for <config>
  • status-led-config-show-heartbeat = 2, for <config>
  • status-led-config-show-status = 3, for <config>
tinkerforge call rs485-bricklet <uid> get-status-led-config
Output:
  • config -- int (has symbols)

Returns the configuration as set by set-status-led-config

The following symbols are available for this function:

  • status-led-config-off = 0, for config
  • status-led-config-on = 1, for config
  • status-led-config-show-heartbeat = 2, for config
  • status-led-config-show-status = 3, for config
tinkerforge call rs485-bricklet <uid> get-chip-temperature
Output:
  • temperature -- int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

tinkerforge call rs485-bricklet <uid> reset
Output:no output

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

tinkerforge call rs485-bricklet <uid> write-uid <uid>
Parameters:
  • <uid> -- int
Output:

no output

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

tinkerforge call rs485-bricklet <uid> read-uid
Output:
  • uid -- int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

tinkerforge call rs485-bricklet <uid> get-identity
Output:
  • uid -- string
  • connected-uid -- string
  • position -- char
  • hardware-version -- int,int,int
  • firmware-version -- int,int,int
  • device-identifier -- int (has symbols)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here

Callback Configuration Functions

tinkerforge call rs485-bricklet <uid> enable-read-callback
Output:no output

Enables the read callback.

By default the callback is disabled.

tinkerforge call rs485-bricklet <uid> disable-read-callback
Output:no output

Disables the read callback.

By default the callback is disabled.

tinkerforge call rs485-bricklet <uid> is-read-callback-enabled
Output:
  • enabled -- bool

Returns true if the read callback is enabled, false otherwise.

tinkerforge call rs485-bricklet <uid> enable-error-count-callback
Output:no output

Enables the error-count callback.

By default the callback is disabled.

tinkerforge call rs485-bricklet <uid> disable-error-count-callback
Output:no output

Disables the error-count callback.

By default the callback is disabled.

tinkerforge call rs485-bricklet <uid> is-error-count-callback-enabled
Output:
  • enabled -- bool

Returns true if the error-count callback is enabled, false otherwise.

Callbacks

Callbacks can be used to receive time critical or recurring data from the device:

tinkerforge dispatch rs485-bricklet <uid> example

The available callbacks are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

tinkerforge dispatch rs485-bricklet <uid> read-low-level
Output:
  • message-length -- int
  • message-chunk-offset -- int
  • message-chunk-data -- char,char,..57x..,char

This callback is called if new data is available.

To enable this callback, use enable-read-callback.

tinkerforge dispatch rs485-bricklet <uid> error-count
Output:
  • overrun-error-count -- int
  • parity-error-count -- int

This callback is called if a new error occurs. It returns the current overrun and parity error count.

tinkerforge dispatch rs485-bricklet <uid> modbus-slave-read-coils-request
Output:
  • request-id -- int
  • starting-address -- int
  • count -- int

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read coils. The parameters are request ID of the request, the starting address and the number of coils to be read as received by the request.

To send a response of this request use modbus-slave-answer-read-coils-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-read-coils-response-low-level
Output:
  • request-id -- int
  • exception-code -- int (has symbols)
  • coils-length -- int
  • coils-chunk-offset -- int
  • coils-chunk-data -- bool,bool,..461x..,bool

This callback is called only in Modbus master mode when the master receives a valid response of a request to read coils.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timed out or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-read-holding-registers-request
Output:
  • request-id -- int
  • starting-address -- int
  • count -- int

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read holding registers. The parameters are request ID of the request, the starting address and the number of holding registers to be read as received by the request.

To send a response of this request use modbus-slave-answer-read-holding-registers-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-read-holding-registers-response-low-level
Output:
  • request-id -- int
  • exception-code -- int (has symbols)
  • holding-registers-length -- int
  • holding-registers-chunk-offset -- int
  • holding-registers-chunk-data -- int,int,..26x..,int

This callback is called only in Modbus master mode when the master receives a valid response of a request to read holding registers.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timed out or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-write-single-coil-request
Output:
  • request-id -- int
  • coil-address -- int
  • coil-value -- bool

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write a single coil. The parameters are request ID of the request, the coil address and the value of coil to be written as received by the request.

To send a response of this request use modbus-slave-answer-write-single-coil-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-write-single-coil-response
Output:
  • request-id -- int
  • exception-code -- int (has symbols)

This callback is called only in Modbus master mode when the master receives a valid response of a request to write a single coil.

The parameters are request ID of the request and exception code of the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timed out or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-write-single-register-request
Output:
  • request-id -- int
  • register-address -- int
  • register-value -- int

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write a single register. The parameters are request ID of the request, the register address and the register value to be written as received by the request.

To send a response of this request use modbus-slave-answer-write-single-register-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-write-single-register-response
Output:
  • request-id -- int
  • exception-code -- int (has symbols)

This callback is called only in Modbus master mode when the master receives a valid response of a request to write a single register.

The parameters are request ID of the request and exception code of the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timed out or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-write-multiple-coils-request-low-level
Output:
  • request-id -- int
  • starting-address -- int
  • coils-length -- int
  • coils-chunk-offset -- int
  • coils-chunk-data -- bool,bool,..437x..,bool

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write multiple coils. The parameters are request ID of the request, the starting address and the data to be written as received by the request.

To send a response of this request use modbus-slave-answer-write-multiple-coils-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-write-multiple-coils-response
Output:
  • request-id -- int
  • exception-code -- int (has symbols)

This callback is called only in Modbus master mode when the master receives a valid response of a request to read coils.

The parameters are request ID of the request and exception code of the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-write-multiple-registers-request-low-level
Output:
  • request-id -- int
  • starting-address -- int
  • registers-length -- int
  • registers-chunk-offset -- int
  • registers-chunk-data -- int,int,..24x..,int

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write multiple registers. The parameters are request ID of the request, the starting address and the data to be written as received by the request.

To send a response of this request use modbus-slave-answer-write-multiple-registers-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-write-multiple-registers-response
Output:
  • request-id -- int
  • exception-code -- int (has symbols)

This callback is called only in Modbus master mode when the master receives a valid response of a request to write multiple registers.

The parameters are request ID of the request and exception code of the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-read-discrete-inputs-request
Output:
  • request-id -- int
  • starting-address -- int
  • count -- int

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read discrete inputs. The parameters are request ID of the request, the starting address and the number of discrete inputs to be read as received by the request.

To send a response of this request use modbus-slave-answer-read-discrete-inputs-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-read-discrete-inputs-response-low-level
Output:
  • request-id -- int
  • exception-code -- int (has symbols)
  • discrete-inputs-length -- int
  • discrete-inputs-chunk-offset -- int
  • discrete-inputs-chunk-data -- bool,bool,..461x..,bool

This callback is called only in Modbus master mode when the master receives a valid response of a request to read discrete inputs.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code
tinkerforge dispatch rs485-bricklet <uid> modbus-slave-read-input-registers-request
Output:
  • request-id -- int
  • starting-address -- int
  • count -- int

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read input registers. The parameters are request ID of the request, the starting address and the number of input registers to be read as received by the request.

To send a response of this request use modbus-slave-answer-read-input-registers-request.

tinkerforge dispatch rs485-bricklet <uid> modbus-master-read-input-registers-response-low-level
Output:
  • request-id -- int
  • exception-code -- int (has symbols)
  • input-registers-length -- int
  • input-registers-chunk-offset -- int
  • input-registers-chunk-data -- int,int,..26x..,int

This callback is called only in Modbus master mode when the master receives a valid response of a request to read input registers.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than zero then the number represents a Modbus exception code. If it is less than zero then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by set-modbus-configuration.

The following symbols are available for this function:

  • exception-code-timeout = -1, for exception-code
  • exception-code-success = 0, for exception-code
  • exception-code-illegal-function = 1, for exception-code
  • exception-code-illegal-data-address = 2, for exception-code
  • exception-code-illegal-data-value = 3, for exception-code
  • exception-code-slave-device-failure = 4, for exception-code
  • exception-code-acknowledge = 5, for exception-code
  • exception-code-slave-device-busy = 6, for exception-code
  • exception-code-memory-parity-error = 8, for exception-code
  • exception-code-gateway-path-unavailable = 10, for exception-code
  • exception-code-gateway-target-device-failed-to-respond = 11, for exception-code