Raypak B6000 11.4.0Modbus Protocol Support, 11.4.1Modbus Commands, Function, Address, Code, Range

11.4.0Modbus Protocol Support

11.4.1Modbus Commands

The T-3 card supports a command subset of the Modbus Specification consisting primarily of the Function Codes required to read and write data. The following sections detail the different commands supported by the card.

Function	Address	Slave Driver
Code	Command	Range	Comments
2	Read Input Status	10001	Module returns binary data from the
		to “Input Status”	register space.
		10331 & 10833
3	Read Multiple	40001	The Module returns word data from
	Registers	to	the register space. The module will
		40138	support up to 125 words of data in
			one command.
4	Read Input Registers	30001	The module returns data from the
		to	“Input register” space in the module.
		30138	The module will support up to 125
			words of data in one command.
6	Single Register Write	40001 to 40030	This is a register write command
		and	allowing a host to change values in
		40133 to 40138	the B6000 unit by writing a register
			value.
8	Loopback Test	Test 0	This is a diagnostic command which
			echoes the command sent.

11.4.2Modbus Error Codes

The T-3 card supports the following Modbus Error Codes:

Code	Name	Description
0	All OK	The module is operating as desired
1	Illegal Functions	An illegal function code request is being attempted
2	Bad Data Address	The address, or the range of addresses, covered by
		a request from the master are not within allowed
		limits.
3	Bad Data Value	The value in the data field of the command is not
		allowed.
4	Incomplete Response	This error indicates that an incomplete response was
	Detected	received to a master query. Often this will indicate
		that the slave device may be responding too quickly
		or that there may be excessive noise on the line.
6	Module Busy	The module busy status code is returned when a
		write command from the master has not yet been
		completed when a second write command is received

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