IF-14

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-14G States of Inputs	Digital Input 1	DI#33	bit	R	0 = inactive 1 = active	3033
	Digital Input 2	DI#34	bit	R		3034
	Digital Input 3	DI#35	bit	R		3035
	Digital Input 4	DI#36	bit	R		3036
	Inputs	DI#33 - DI#48	u16	R	0x0000 - 0x000F