RE8.2

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

Subject		Channel	Type	R/W	Value	Offset
States of Relay Outputs	COIL Relay 1	DI#01	bit	R	0 = inactive 1 = active	3001
	COIL Relay 2	DI#02	bit	R		3002
	COIL Relay 3	DI#03	bit	R		3003
	COIL Relay 4	DI#04	bit	R		3004
	COIL Relay 5	DI#05	bit	R		3005
	COIL Relay 6	DI#06	bit	R		3006
	COIL Relay 7	DI#07	bit	R		3007
	COIL Relay 8	DI#08	bit	R		3008
	Inputs	DI#16 - DI#01	u16	R	0x0000 - 0x00FF	3001

Subject		Channel	Type	R/W	Value	Offset
Relay Outputs	Relay Output 1	DO#01	bit	RW	0 = inactive 1 = active	4001
	Relay Output 2	DO#02	bit	RW		4002
	Relay Output 3	DO#03	bit	RW		4003
	Relay Output 4	DO#04	bit	RW		4004
	Relay Output 5	DO#05	bit	RW		4005
	Relay Output 6	DO#06	bit	RW		4006
	Relay Output 7	DO#07	bit	RW		4007
	Relay Output 8	DO#08	bit	RW		4008
	Outputs	DO#16 - DO#01	u16	RW	0x0000 - 0x00FF	4001

Note: To activate the bootloader, it is necessary to write a value 617 into the registry with an offset 1204 and restart the device.