Pneumercator MODBUS RTU RS-485 Instruction Manual page 7

2.0 MODBUS Function Format
Function Code 3: Read Holding Registers
Note: All Queries are in Hex RTU format
Master to Slave (TMS/LC2000) Query – Read TMS/LC2000 Data
CHAR # 1
SLA
Slave (TMS/LC2000) to Master Response – Read TMS/LC2000 Data
CHAR # 1
SLA
MODBUS RTU Instruction Manual - 2017-11-02.docx
2 3 4
FC STA
2 3 4
FC BC DATA
5 6 7
NPR EC
BC+3 BC+4 BC+5
EC
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Error Check - 16-bit CRC
Number of Points to Read
Start Address
Function Code (03H)
Slave Address (00H - 0FH)
Error Check - 16-bit CRC
Data Stream
Byte Count
Function Code (03H)
Slave Address (00H - 0FH)
November 2, 2017