cheap_modbus_rtu.cheap_modbus_io.Relay4Ch Class Reference

Control via RS-485 Modbus RTU: More...

Public Member Functions
def	__init__ (self, int slave_id=255, str serial_device_name=None, int baudrate=9600, **kwargs)
def	set_output (self, int output_no, bool active=True)
	Set specified output. More...
def	clear_output (self, int output_no)
	Disable specified output. More...
bool	get_input (self, int input_no)
	Return the state of the specified digital input. More...
tuple[bool,...]	get_inputs (self)
	Returns the state of the digital inputs. More...
def	set_slave_id (self, int slave_id_new)
	Set the slave ID. More...
def	set_baudrate (self, int baudrate=9600)
	Set RS485 serial baud rate. More...
def	do_factory_reset (self)
	Factory reset not implemented for the relay modules.
int	get_slave_id (self)
	Sends a broadcast query to all devices on the bus. More...

Public Attributes
	slave_id
	master

Static Public Attributes
int	NUM_IOS = 4
int	DI_REGISTER = 10001
int	SLAVE_ID_REGISTER = 40001
int	BAUDRATE_REGISTER = 41002
int	BROADCAST_SLAVE_ID = 0
dictionary	BAUDRATE_KEYS = {1200: 0, 2400: 1, 4800: 2, 9600: 3, 19200: 4}

Detailed Description

Control via RS-485 Modbus RTU:

1x Serial RS-485 Modbus RTU relay PCB

==> This is for the four-channel variant.

This variant has:

• four relay outputs and
• four functionally isolated digital inputs

Member Function Documentation

clear_output()

def cheap_modbus_rtu.cheap_modbus_io.RelayModule.clear_output (   self, int  output_no  )

inherited

Disable specified output.

Parameters

output_no

Output number, starts counting at 1

get_input()

bool cheap_modbus_rtu.cheap_modbus_io.RelayModule.get_input (   self, int  input_no  )

inherited

Return the state of the specified digital input.

Parameters

input_no

Input number, starts counting at 1

Returns

True if input signal is active, False if inactive

get_inputs()

tuple[bool, ...] cheap_modbus_rtu.cheap_modbus_io.RelayModule.get_inputs (   self )

inherited

Returns the state of the digital inputs.

Returns

Tuple of boolean flags, one for each input

get_slave_id()

int cheap_modbus_rtu.cheap_modbus_io.ModbusModuleABC.get_slave_id (   self )

inherited

Sends a broadcast query to all devices on the bus.

   This only works when only one device is attached to the bus

Returns

The first found slave ID.

set_baudrate()

def cheap_modbus_rtu.cheap_modbus_io.RelayModule.set_baudrate (   self, int   baudrate = 9600  )

inherited

Set RS485 serial baud rate.

Warning

While undocumented, it is possible that the device writes directly to FLASH, thus frequent writes could damage the chip!

Parameters

FIXME	1200 and 2400 are undocumented. Really possible?
baudrate	Can be 1200, 2400, 4800, 9600 (default) or 19200

Reimplemented from cheap_modbus_rtu.cheap_modbus_io.ModbusModuleABC.

set_output()

def cheap_modbus_rtu.cheap_modbus_io.RelayModule.set_output (   self, int  output_no, bool   active = True  )

inherited

Set specified output.

Parameters

output_no	Output number, starts counting at 1
active	Enable output if active == True (default) Disable output if active == False

set_slave_id()

def cheap_modbus_rtu.cheap_modbus_io.RelayModule.set_slave_id (   self, int  slave_id_new  )

inherited

Set the slave ID.

Warning

While usually undocumented, it is possible that the device writes directly to FLASH, thus frequent writes could damage the chip!

Parameters

slave_id_new

New Modbus slave ID

Reimplemented from cheap_modbus_rtu.cheap_modbus_io.ModbusModuleABC.

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The documentation for this class was generated from the following file:

• src/cheap_modbus_rtu/cheap_modbus_io.py