Modbus Function Code 0X03 Demonstration - DAUDIN iO-GRID m User Manual

7.2 Modbus function code 0x03 Demonstration

I. Use Modbus RTU/ASCII to read single-chip counter module registers
Modbus function code
0x03
※In this example, we are reading "0x1000 and 0x1001 channel 1" with the I/O
module ID of "01"
※When not using control modules for communications, the addresses for the
registers will be:0x1000 (CH0 high-order word), 0x1001 (CH0 low-order word),
0x1002 (CH1 high-order word), 0x1003 (CH1 low-order word), 0x1004 (CH2 high-
order word), 0x1005 (CH2 low-order word), 0x1006 (CH3 high-order word) and
0x1007 (CH3 low-order word).
II. Use Modbus RTU/ASCII with control modules to read analog input registers
Modbus function code
0x03
※In this example, we are reading "0x1000 and 0x1001 channel 1" with the control
module ID of "01"
※When using control modules for communications, the addresses for the registers
will start at: 0x1000 (CH0 high-order word), 0x1001 (CH0 low-order word), 0x1002
(CH1 high-order word), 0x1003 (CH1 low-order word), 0x1004 (CH2 high-order
word), 0x1005 (CH2 low-order word), 0x1006 (CH3 high-order word) and 0x1007
(CH3 low-order word).
Transmission example
(ID:0x01)
01 03 10 00 00 02
Transmission example
(ID:0x01)
01 03 10 00 00 02
23
Respond example (ID:0x01)
01 03 04 00 00 00 00
Respond example (ID:0x01)
01 03 04 00 00 00 00