IF-15

Modbus Registers

Below is a list of available MODBUS registers. The same register numbers are also used by the MIOS-2 protocol.

Modbus Read / Write (0x17) Function

METEL IO modules have implemented the MODBUS function (0x17) Read/Write of Multiple registers. Typically it is required to have two separate requests (and responses) for:

1. Writing of outputs via MODBUS function (0x16) Writing Multiple Registers

2. Reading of inputs via MODBUS function (0x03) Read Holding Registers

This requires a total of 4 frames to be sent over MODBUS. If using 0x17 function only one request is needed for the reading and writing of outputs. This requires a total of 2 frames to be sent over MODBUS.

Default Settings of Communication

Device ID: 1
Baudrate: 115 200
Parity: None
Data bits: 8
Stop bits: 1

Note: The MODBUS address is the same as the address of the main device of which the IF module is part.

Subject		Channel	Type	R/W	Value	Offset
IF-15(G) States of Inputs	Open Collector 1	DO#33	bit	RW	0 = inactive 1 = active	4033
	Open Collector 2	DO#34	bit	RW		4034
	Open Collector 3	DO#35	bit	RW		4035
	Open Collector 4	DO#36	bit	RW		4036
	Outputs	DI#33 - DI#48	u16	R	0x0000 - 0x000F