Modbus - Industrial Digital Out 4 Bricklet

This is the description of the Modbus protocol for the Industrial Digital Out 4 Bricklet. General information and technical specifications for the Industrial Digital Out 4 Bricklet are summarized in its hardware description.

API

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

Basic Functions

BrickletIndustrialDigitalOut4.set_value
Function ID:

1

Request:
  • value_mask -- uint16
Response:

no response

Sets the output value with a bitmask (16bit). A 1 in the bitmask means high and a 0 in the bitmask means low.

For example: The value 3 or 0b0011 will turn pins 0-1 high and the other pins low.

If no groups are used (see set_group), the pins correspond to the markings on the Digital Out 4 Bricklet.

If groups are used, the pins correspond to the element in the group. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

BrickletIndustrialDigitalOut4.get_value
Function ID:

2

Request:

empty payload

Response:
  • value_mask -- uint16

Returns the bitmask as set by set_value.

BrickletIndustrialDigitalOut4.set_selected_values
Function ID:

9

Request:
  • selection_mask -- uint16
  • value_mask -- uint16
Response:

no response

Sets the output value with a bitmask, according to the selection mask. The bitmask is 16 bit long, true refers to high and false refers to low.

For example: The values (3, 1) or (0b0011, 0b0001) will turn pin 0 high, pin 1 low the other pins remain untouched.

If no groups are used (see set_group), the pins correspond to the markings on the Digital Out 4 Bricklet.

If groups are used, the pins correspond to the element in the group. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

Advanced Functions

BrickletIndustrialDigitalOut4.set_monoflop
Function ID:

3

Request:
  • selection_mask -- uint16
  • value_mask -- uint16
  • time -- uint32
Response:

no response

Configures a monoflop of the pins specified by the first parameter bitmask.

The second parameter is a bitmask with the desired value of the specified pins. A 1 in the bitmask means high and a 0 in the bitmask means low.

The third parameter indicates the time (in ms) that the pins should hold the value.

If this function is called with the parameters (9, 1, 1500) or (0b1001, 0b0001, 1500): Pin 0 will get high and pin 3 will get low. In 1.5s pin 0 will get low and pin 3 will get high again.

A monoflop can be used as a fail-safe mechanism. For example: Lets assume you have a RS485 bus and a Digital Out 4 Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds and pin 0 high. Pin 0 will be high all the time. If now the RS485 connection is lost, then pin 0 will turn low in at most two seconds.

BrickletIndustrialDigitalOut4.get_monoflop
Function ID:

4

Request:
  • pin -- uint8
Response:
  • value -- uint16
  • time -- uint32
  • time_remaining -- uint32

Returns (for the given pin) the current value and the time as set by set_monoflop as well as the remaining time until the value flips.

If the timer is not running currently, the remaining time will be returned as 0.

BrickletIndustrialDigitalOut4.set_group
Function ID:

5

Request:
  • group -- char[4]
Response:

no response

Sets a group of Digital Out 4 Bricklets that should work together. You can find Bricklets that can be grouped together with get_available_for_group.

The group consists of 4 elements. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

Each element can either be one of the ports ('a' to 'd') or 'n' if it should not be used.

For example: If you have two Digital Out 4 Bricklets connected to port A and port B respectively, you could call with ['a', 'b', 'n', 'n'].

Now the pins on the Digital Out 4 on port A are assigned to 0-3 and the pins on the Digital Out 4 on port B are assigned to 4-7. It is now possible to call set_value and control two Bricklets at the same time.

BrickletIndustrialDigitalOut4.get_group
Function ID:

6

Request:

empty payload

Response:
  • group -- char[4]

Returns the group as set by set_group

BrickletIndustrialDigitalOut4.get_available_for_group
Function ID:

7

Request:

empty payload

Response:
  • available -- uint8

Returns a bitmask of ports that are available for grouping. For example the value 5 or 0b0101 means: Port A and port C are connected to Bricklets that can be grouped together.

BrickletIndustrialDigitalOut4.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

Callbacks

BrickletIndustrialDigitalOut4.CALLBACK_MONOFLOP_DONE
Function ID:

8

Response:
  • selection_mask -- uint16
  • value_mask -- uint16

This callback is triggered whenever a monoflop timer reaches 0. The response values contain the involved pins and the current value of the pins (the value after the monoflop).