Master Mode

in	Bus	string	path to bus device (BUS1 = "/dev/ttyS3" or BUS2 = "/dev/ttyS2")
in	Baud	int	standard baudrates from 150 to 115200 (allowed speeds: 150, 300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 38400, 57600, 115200, 1000000)
in	Parity	string[1]	"N" = none, "E" = even, "O" = odd
in	Databit	USINT	Databits (5,6,7,8)
in	Stopbit	USINT	Stopbits (1,2)
out	ERR	bool	indicates some error occurs (0 = OK)
out	ERR_ID	WORD	identifies occured error by unique code

MODBUS_RTU_STATS

The block provides statistical information on the responses from the slave that do not arrive on time. This is useful when debugging timeouts.

in	Bus	string	path to bus device (BUS1 = "/dev/ttyS3" or BUS2 = "/dev/ttyS2")
out	TIMEOUT_CNT	UDINT	A counter of responses that do not arrive within the time limit.
out	FLUSH_CNT	UDINT	A counter of responses that arrive after a timeout.
out	DBG_TEXT	string[255]	String of the last flushed data.

Example of usage:

MODBUS_RTU_R_COIL

Reads one coil register

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q	bool	readed value

MODBUS_RTU_R_COIL_8

Reads up to 8 coil registers

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to read (1-8)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q1	bool	readed value of 1st register
out	Q2	bool	readed value of 2nd register
out	Q3	bool	readed value of 3rd register
out	Q4	bool	readed value of 4th register
out	Q5	bool	readed value of 5th register
out	Q6	bool	readed value of 6th register
out	Q7	bool	readed value of 7th register
out	Q8	bool	readed value of 8th register

MODBUS_RTU_R_DISCRETE

Read one discrete input register

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q	bool	readed value

MODBUS_RTU_R_DISCRETE_8

Read up to 8 discrete input registers

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to read (1-8)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q1	bool	readed value of 1st register
out	Q2	bool	readed value of 2nd register
out	Q3	bool	readed value of 3rd register
out	Q4	bool	readed value of 4th register
out	Q5	bool	readed value of 5th register
out	Q6	bool	readed value of 6th register
out	Q7	bool	readed value of 7th register
out	Q8	bool	readed value of 8th register

MODBUS_RTU_R_HOLDING

Reads one holding register

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q	word	readed value

MODBUS_RTU_R_HOLDING_8

Reads up to 8 holding registers

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to read (1-8)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q1	bool	readed value of 1st register
out	Q2	bool	readed value of 2nd register
out	Q3	bool	readed value of 3rd register
out	Q4	bool	readed value of 4th register
out	Q5	bool	readed value of 5th register
out	Q6	bool	readed value of 6th register
out	Q7	bool	readed value of 7th register
out	Q8	bool	readed value of 8th register

MODBUS_RTU_R2_HOLDING

Reads two holding registers as 32bit number (lower register with higher weight)

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q	dword	readed value

MODBUS_RTU_R_INPUT

Reads one input register

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q	word	readed value

MODBUS_RTU_R_INPUT_8

Reads up to 8 input registers

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to read (1-8)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q1	bool	readed value of 1st register
out	Q2	bool	readed value of 2nd register
out	Q3	bool	readed value of 3rd register
out	Q4	bool	readed value of 4th register
out	Q5	bool	readed value of 5th register
out	Q6	bool	readed value of 6th register
out	Q7	bool	readed value of 7th register
out	Q8	bool	readed value of 8th register

MODBUS_RTU_R2_INPUT

Reads two input registers as 32bit number (lower register with higher weight)

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
out	Q	dword	readed value

MODBUS_RTU_W_COIL

Writes value to one coil register

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
in	VAL	bool	value to write

MODBUS_RTU_W_COIL_8

Writes value to up to 8 coil registers

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to write (1-8)
in	Timeout	byte	timeout in seconds (default: 250ms)
in	VAL1	bool	value to write to 1st register
in	VAL2	bool	value to write to 2nd register
in	VAL3	bool	value to write to 3rd register
in	VAL4	bool	value to write to 4th register
in	VAL5	bool	value to write to 5th register
in	VAL6	bool	value to write to 6th register
in	VAL7	bool	value to write to 7th register
in	VAL8	bool	value to write to 8th register

MODBUS_RTU_W_HOLDING

Writes value to one holding register

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
in	VAL	word	value to write

MODBUS_RTU_W_HOLDING_8

Writes value to up to 8 holding registers

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to write (1-8)
in	Timeout	byte	timeout in seconds (default: 250ms)
in	VAL1	bool	value to write to 1st register
in	VAL2	bool	value to write to 2nd register
in	VAL3	bool	value to write to 3rd register
in	VAL4	bool	value to write to 4th register
in	VAL5	bool	value to write to 5th register
in	VAL6	bool	value to write to 6th register
in	VAL7	bool	value to write to 7th register
in	VAL8	bool	value to write to 8th register

MODBUS_RTU_W2_HOLDING

Writes value to two holding registers (lower register with higher weight)

Asynchronous interface - internal implementation
in	Bus	string	path to bus device (/dev/ttyS0)
in	UnitID	byte	device bus address (0-247)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 250ms)
in	VAL	dword	value to write

TCP

MODBUS_TCP_R_COIL

Reads one coil register

Asynchronous interface - internal implementation
in	IP	string	IP address of slave device (syntax: "aaa.bbb.ccc.ddd")
in	Port	int	TCP port of slave device (default: 502)
in	UnitID	byte	Device bus address (default: 1)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 1s)
out	Q	bool	readed value

MODBUS_TCP_R_COIL_8

Reads up to 8 coil registers

Asynchronous interface - internal implementation
in	IP	string	IP address of slave device (syntax: "aaa.bbb.ccc.ddd")
in	Port	int	TCP port of slave device (default: 502)
in	UnitID	byte	Device bus address (default: 1)
in	OfsAdr	word	register address (1-9999)
in	Count	byte	number of registers to read (1-8)
in	Timeout	byte	timeout in seconds (default: 1s)
out	Q1	bool	readed value of 1st register
out	Q2	bool	readed value of 2nd register
out	Q3	bool	readed value of 3rd register
out	Q4	bool	readed value of 4th register
out	Q5	bool	readed value of 5th register
out	Q6	bool	readed value of 6th register
out	Q7	bool	readed value of 7th register
out	Q8	bool	readed value of 8th register

MODBUS_TCP_R_DISCRETE

Read one discrete input register

Asynchronous interface - internal implementation
in	IP	string	IP address of slave device (syntax: "aaa.bbb.ccc.ddd")
in	Port	int	TCP port of slave device (default: 502)
in	UnitID	byte	Device bus address (default: 1)
in	OfsAdr	word	register address (1-9999)
in	Timeout	byte	timeout in seconds (default: 1s)
out	Q	bool	readed value

MODBUS_TCP_R_DISCRETE_8