Modbus - Industrial Dual 0-20mA Bricklet 2.0

This is the description of the Modbus protocol for the Industrial Dual 0-20mA Bricklet 2.0. General information and technical specifications for the Industrial Dual 0-20mA Bricklet 2.0 are summarized in its hardware description.

API

A general description of the Modbus protocol structure can be found here.

Basic Functions

BrickletIndustrialDual020mAV2.get_current
Function ID:

1

Request:
  • channel -- uint8
Response:
  • current -- int32

Returns the current of the specified channel. The value is in nA and between 0nA and 22505322nA (22.5mA).

It is possible to detect if an IEC 60381-1 compatible sensor is connected and if it works probably.

If the returned current is below 4mA, there is likely no sensor connected or the connected sensor is defective. If the returned current is over 20mA, there might be a short circuit or the sensor is defective.

If you want to get the value periodically, it is recommended to use the CALLBACK_CURRENT callback. You can set the callback configuration with set_current_callback_configuration.

BrickletIndustrialDual020mAV2.set_channel_led_config
Function ID:

9

Request:
  • channel -- uint8
  • config -- uint8
Response:

no response

Each channel has a corresponding LED. You can turn the LED off, on or show a heartbeat. You can also set the LED to "Channel Status". In this mode the LED can either be turned on with a pre-defined threshold or the intensity of the LED can change with the measured value.

You can configure the channel status behavior with set_channel_led_status_config.

By default all channel LEDs are configured as "Channel Status".

The following meanings are defined for the parameters of this function:

  • 0: off, for config
  • 1: on, for config
  • 2: show heartbeat, for config
  • 3: show channel status, for config
BrickletIndustrialDual020mAV2.get_channel_led_config
Function ID:

10

Request:
  • channel -- uint8
Response:
  • config -- uint8

Returns the channel LED configuration as set by set_channel_led_config

The following meanings are defined for the parameters of this function:

  • 0: off, for config
  • 1: on, for config
  • 2: show heartbeat, for config
  • 3: show channel status, for config
BrickletIndustrialDual020mAV2.set_channel_led_status_config
Function ID:

11

Request:
  • channel -- uint8
  • min -- int32
  • max -- int32
  • config -- uint8
Response:

no response

Sets the channel LED status config. This config is used if the channel LED is configured as "Channel Status", see set_channel_led_config.

For each channel you can choose between threshold and intensity mode.

In threshold mode you can define a positive or a negative threshold. For a positive threshold set the "min" parameter to the threshold value in nA above which the LED should turn on and set the "max" parameter to 0. Example: If you set a positive threshold of 10mA, the LED will turn on as soon as the current exceeds 10mA and turn off again if it goes below 10mA. For a negative threshold set the "max" parameter to the threshold value in nA below which the LED should turn on and set the "min" parameter to 0. Example: If you set a negative threshold of 10mA, the LED will turn on as soon as the current goes below 10mA and the LED will turn off when the current exceeds 10mA.

In intensity mode you can define a range in nA that is used to scale the brightness of the LED. Example with min=4mA and max=20mA: The LED is off at 4mA and below, on at 20mA and above and the brightness is linearly scaled between the values 4mA and 20mA. If the min value is greater than the max value, the LED brightness is scaled the other way around.

By default the channel LED status config is set to intensity with min=4mA and max=20mA.

The following meanings are defined for the parameters of this function:

  • 0: threshold, for config
  • 1: intensity, for config
BrickletIndustrialDual020mAV2.get_channel_led_status_config
Function ID:

12

Request:
  • channel -- uint8
Response:
  • min -- int32
  • max -- int32
  • config -- uint8

Returns the channel LED status configuration as set by set_channel_led_status_config.

The following meanings are defined for the parameters of this function:

  • 0: threshold, for config
  • 1: intensity, for config

Advanced Functions

BrickletIndustrialDual020mAV2.set_sample_rate
Function ID:

5

Request:
  • rate -- uint8
Response:

no response

Sets the sample rate to either 240, 60, 15 or 4 samples per second. The resolution for the rates is 12, 14, 16 and 18 bit respectively.

Value Description
0 240 samples per second, 12 bit resolution
1 60 samples per second, 14 bit resolution
2 15 samples per second, 16 bit resolution
3 4 samples per second, 18 bit resolution

The default value is 3 (4 samples per second with 18 bit resolution).

The following meanings are defined for the parameters of this function:

  • 0: 240 sps, for rate
  • 1: 60 sps, for rate
  • 2: 15 sps, for rate
  • 3: 4 sps, for rate
BrickletIndustrialDual020mAV2.get_sample_rate
Function ID:

6

Request:

empty payload

Response:
  • rate -- uint8

Returns the gain as set by set_sample_rate.

The following meanings are defined for the parameters of this function:

  • 0: 240 sps, for rate
  • 1: 60 sps, for rate
  • 2: 15 sps, for rate
  • 3: 4 sps, for rate
BrickletIndustrialDual020mAV2.set_gain
Function ID:

7

Request:
  • gain -- uint8
Response:

no response

Sets a gain between 1x and 8x. If you want to measure a very small current, you can increase the gain to get some more resolution.

Example: If you measure 0.5mA with a gain of 8x the return value will be 4mA.

The default gain is 1x.

The following meanings are defined for the parameters of this function:

  • 0: 1x, for gain
  • 1: 2x, for gain
  • 2: 4x, for gain
  • 3: 8x, for gain
BrickletIndustrialDual020mAV2.get_gain
Function ID:

8

Request:

empty payload

Response:
  • gain -- uint8

Returns the gain as set by set_gain.

The following meanings are defined for the parameters of this function:

  • 0: 1x, for gain
  • 1: 2x, for gain
  • 2: 4x, for gain
  • 3: 8x, for gain
BrickletIndustrialDual020mAV2.get_spitfp_error_count
Function ID:

234

Request:

empty payload

Response:
  • error_count_ack_checksum -- uint32
  • error_count_message_checksum -- uint32
  • error_count_frame -- uint32
  • error_count_overflow -- uint32

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.

BrickletIndustrialDual020mAV2.set_bootloader_mode
Function ID:

235

Request:
  • mode -- uint8
Response:
  • status -- uint8

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 meanings are defined for the parameters of this function:

  • 0: bootloader, for mode
  • 1: firmware, for mode
  • 2: bootloader wait for reboot, for mode
  • 3: firmware wait for reboot, for mode
  • 4: firmware wait for erase and reboot, for mode
  • 0: ok, for status
  • 1: invalid mode, for status
  • 2: no change, for status
  • 3: entry function not present, for status
  • 4: device identifier incorrect, for status
  • 5: crc mismatch, for status
BrickletIndustrialDual020mAV2.get_bootloader_mode
Function ID:

236

Request:

empty payload

Response:
  • mode -- uint8

Returns the current bootloader mode, see set_bootloader_mode.

The following meanings are defined for the parameters of this function:

  • 0: bootloader, for mode
  • 1: firmware, for mode
  • 2: bootloader wait for reboot, for mode
  • 3: firmware wait for reboot, for mode
  • 4: firmware wait for erase and reboot, for mode
BrickletIndustrialDual020mAV2.set_write_firmware_pointer
Function ID:

237

Request:
  • pointer -- uint32
Response:

no response

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.

BrickletIndustrialDual020mAV2.write_firmware
Function ID:

238

Request:
  • data -- uint8[64]
Response:
  • status -- uint8

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.

BrickletIndustrialDual020mAV2.set_status_led_config
Function ID:

239

Request:
  • config -- uint8
Response:

no response

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 meanings are defined for the parameters of this function:

  • 0: off, for config
  • 1: on, for config
  • 2: show heartbeat, for config
  • 3: show status, for config
BrickletIndustrialDual020mAV2.get_status_led_config
Function ID:

240

Request:

empty payload

Response:
  • config -- uint8

Returns the configuration as set by set_status_led_config

The following meanings are defined for the parameters of this function:

  • 0: off, for config
  • 1: on, for config
  • 2: show heartbeat, for config
  • 3: show status, for config
BrickletIndustrialDual020mAV2.get_chip_temperature
Function ID:

242

Request:

empty payload

Response:
  • temperature -- int16

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.

BrickletIndustrialDual020mAV2.reset
Function ID:243
Request:empty payload
Response:no response

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!

BrickletIndustrialDual020mAV2.write_uid
Function ID:

248

Request:
  • uid -- uint32
Response:

no response

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.

BrickletIndustrialDual020mAV2.read_uid
Function ID:

249

Request:

empty payload

Response:
  • uid -- uint32

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

BrickletIndustrialDual020mAV2.get_identity
Function ID:

255

Request:

empty payload

Response:
  • uid -- char[8]
  • connected_uid -- char[8]
  • position -- char
  • hardware_version -- uint8[3]
  • firmware_version -- uint8[3]
  • device_identifier -- uint16

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

BrickletIndustrialDual020mAV2.set_current_callback_configuration
Function ID:

2

Request:
  • channel -- uint8
  • period -- uint32
  • value_has_to_change -- bool
  • option -- char
  • min -- int32
  • max -- int32
Response:

no response

The period in ms is the period with which the CALLBACK_CURRENT callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_CURRENT callback.

The following options are possible:

Option Description
'x' Threshold is turned off
'o' Threshold is triggered when the value is outside the min and max values
'i' Threshold is triggered when the value is inside or equal to the min and max values
'<' Threshold is triggered when the value is smaller than the min value (max is ignored)
'>' Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletIndustrialDual020mAV2.get_current_callback_configuration
Function ID:

3

Request:
  • channel -- uint8
Response:
  • period -- uint32
  • value_has_to_change -- bool
  • option -- char
  • min -- int32
  • max -- int32

Returns the callback configuration as set by set_current_callback_configuration.

The following meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option

Callbacks

BrickletIndustrialDual020mAV2.CALLBACK_CURRENT
Function ID:

4

Response:
  • channel -- uint8
  • current -- int32

This callback is triggered periodically according to the configuration set by set_current_callback_configuration.

The response value is the same as get_current.