Modbus - Dual Relay Bricklet¶

Basic Functions¶

BrickletDualRelay.set_state¶

Function ID:	1
Request:	relay1 – Type: bool, Default: false relay2 – Type: bool, Default: false
Response:	no response

Sets the state of the relays, true means on and false means off. For example: (true, false) turns relay 1 on and relay 2 off.

If you just want to set one of the relays and don't know the current state of the other relay, you can get the state with get_state or you can use set_selected_state.

All running monoflop timers will be aborted if this function is called.

BrickletDualRelay.get_state¶

Function ID:	2
Request:	empty payload
Response:	relay1 – Type: bool, Default: false relay2 – Type: bool, Default: false

Returns the state of the relays, true means on and false means off.

Advanced Functions¶

BrickletDualRelay.set_monoflop¶

Function ID:	3
Request:	relay – Type: uint8, Range: [1 to 2] state – Type: bool time – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1]
Response:	no response

The first parameter can be 1 or 2 (relay 1 or relay 2). The second parameter is the desired state of the relay (true means on and false means off). The third parameter indicates the time that the relay should hold the state.

If this function is called with the parameters (1, true, 1500): Relay 1 will turn on and in 1.5s it will turn off again.

A monoflop can be used as a failsafe mechanism. For example: Lets assume you have a RS485 bus and a Dual Relay Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds. The relay will be on all the time. If now the RS485 connection is lost, the relay will turn off in at most two seconds.

BrickletDualRelay.get_monoflop¶

Function ID:	4
Request:	relay – Type: uint8, Range: [1 to 2]
Response:	state – Type: bool time – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1] time_remaining – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1]

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

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

BrickletDualRelay.set_selected_state¶

Function ID:	6
Request:	relay – Type: uint8, Range: [1 to 2] state – Type: bool
Response:	no response

Sets the state of the selected relay (1 or 2), true means on and false means off.

A running monoflop timer for the selected relay will be aborted if this function is called.

The other relay remains untouched.

BrickletDualRelay.get_identity¶

Function ID:	255
Request:	empty payload
Response:	uid – Type: char[8] connected_uid – Type: char[8] position – Type: char, Range: ['a' to 'h', 'z'] hardware_version – Type: uint8[3] 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] firmware_version – Type: uint8[3] 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] device_identifier – Type: uint16, Range: [0 to 216 - 1]

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. 

Callbacks¶

BrickletDualRelay.CALLBACK_MONOFLOP_DONE¶

Function ID:	5
Response:	relay – Type: uint8, Range: [1 to 2] state – Type: bool

This callback is triggered whenever a monoflop timer reaches 0. The parameter contain the relay (1 or 2) and the current state of the relay (the state after the monoflop).