Function 0X01 - Read Discrete Coils - Protech Systems SI-W309 User Manual

4.2.1 Function 0x01 – Read Discrete Coils
This function code is used to read the current value of Channel address for SI-W309
module.
Request
Offset Description
00 Slave ID address
01 Function Code
02 ~ 03 Channel address
04 ~ 05
Response-1
The channel address is 0x1000~0x1007, 0x1040~0x1047, 0x1180~0x1187, 0x11C0
and 0x11C1.
Offset Description
00 Slave ID address
01 Function Code
02 Byte Count
03 Output channel
Readback value
04 ~ 05 CRC
Response-2
The channel address is 0x1080~0x108E and 0x1100~0x110E.
Offset Description
00 Slave ID address
01 Function Code
02 Byte Count
03 ~ 4 Output channel
Readback value
05 ~ 06 CRC
SI-W309 SERIES USER MANUAL
Counts
1 Byte
1 Byte
2 Bytes
CRC 2 Bytes
Counts
1 Byte
1 Byte
1 Byte
1 Bytes
2 Bytes
Counts
1 Byte
1 Byte
1 Byte
2 Bytes
2 Bytes
Chapter 4 MODBUS RTU Protocol
Data
1 to 255
0x01
•
0x1000~0x1007: Digital Output
Channel mode Switch
•
0x1040~0x1047: Power-on mode of
Digital Output Channel
•
0x1080~0x108E: High N
millisecond in Clock mode setting of
Digital Output Channel
•
0x1100~0x110E: Low N millisecond
in Clock mode setting of Digital
Output Channel
•
0x1180~0x1187: Digital Input
Channel mode
•
0x11C0: Inverse mode of Digital
output channel
•
0x11C1: Inverse mode of Digital
Input Channel
Produced by utility.
Data
1 to 255
0x01
1
Corresponding to Byte
count
Produced by firmware.
Data
1 to 255
0x01
2
Corresponding to Byte
count
Produced by firmware.
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