Buses

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

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

Subject		Type	R/W	Value	Offset
BUS 1 Settings	Baudrate	u16	RW	192 = 19 200 bps 1152 = 115 200 bps 9246 = 921 600 bps 10000 = 1 000 000bps	2110
	Databits	u16	RW	8 = 8b, 9 = 9b	2111
	Parity	u16	RW	78 = None 69 = Even 79 = Odd	2112
	Stop bits	u16	RW	10=1, 20=2, 15=1,5	2113
	MODBUS address	u16	RW	1 - 247	2120

Subject		Type	R/W	Value	Offset
BUS 2 Settings	Baudrate	u16	RW	192 = 19 200 bps 1152 = 115 200 bps 9246 = 921 600 bps 10000 = 1 000 000bps	2210
	Databits	u16	RW	8 = 8b, 9 = 9b	2211
	Parity	u16	RW	78 = None 69 = Even 79 = Odd	2212
	Stop bits	u16	RW	10=1, 20=2, 15=1,5	2213
	MODBUS address	u16	RW	1 - 247	2220