Function 0X01 - Read Discrete Coils - Protech Systems SI-W509 User Manual

4.2.1 Function 0x01 – Read Discrete Coils
This function code is used to read the current value of Relay output Channel
for SI-W509 module.
Request
Offset Description
00 Slave ID address
01 Function Code
02 ~ 03 Channel address
04 ~ 05 CRC
Response-1
The channel address is 0x1000~0x1005, 0x1040~0x1045, 0x1180~0x1185,
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 0x1080~0x108A and 0x1100~0x110A.
Offset Description
00 Slave ID address
01 Function Code
02 Byte Count
03 ~ 4 Output channel
Readback value
05 ~ 06 CRC
SI-W509 SERIES USER MANUAL
Chapter 4 MODBUS RTU Protocol
Counts
1 Byte 1 to 255
1 Byte 0x01
2 Bytes
•
0x1000~0x1005: Relay Channel
mode Switch
•
0x1040~0x1045: Power-on mode
•
0x1080~0x108A: High N
millisecond in Clock mode setting
•
0x1100~0x110A: Low N millisecond
in Clock mode setting
•
0x1180~0x1185: Relay Channel
mode
•
0x11C0: Inverse mode of Relay
output channel
•
0x11C1: Inverse mode of Digital
Input Channel
2 Bytes Produced by utility.
Counts
1 Byte 1 to 255
1 Byte 0x01
1 Byte 1
Corresponding to Byte
1 Bytes
count
2 Bytes Produced by firmware.
Counts
1 Byte 1 to 255
1 Byte 0x01
1 Byte 2
Corresponding to Byte
2 Bytes
count
2 Bytes Produced by firmware.
Data
Data
Data
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