OleumTech H Series - 7. MODBUS RTU COMMUNICATIONS PROTOCOL; 1. Communication Command List

Page 27
DIFFERENTIAL PRESSURE TRANSMITTER - USER GUIDE
7. MODBUS RTU COMMUNICATIONS PROTOCOL
1. Communication Command List
Items in parentheses are the decimal form of Starting Register / Register
Quantity / Register Value
Starting Address Example:
Table's Starting Address = 4
PLC Starting Address = 30004
Floating Point Starting Address = 7004
*All read register values are float (split 32 -bit).
No. Function Code Starting Address Register Quantity
Byte
Count
Register
Value
Description
1 3 - Read Holding Registers
0
4
No No
Read Pressure & Temperature
0
2
Read Pressure
4
Read Temperature
2 4 - Read Input Registers
4
2 No No
Read Parameter - Lower Limit (SLL), Read Only
8
Read Parameter - Upper Limit (SLH), Read Only
40
Read Parameter - Baud Rate (BT)
44
Read Parameter - Slave Address (DE)
48
Read Parameter - Check Mode (0ddP)
52
Read Parameter - Stop Bit (Stop)
60
Read Parameter - Float Format (FFT)
3 6 - Write Single Registers
0 No No
0
PV Clear
1
Zero Micro Adjustment
2
Full Scale Micro Adjustment
2
No No
222
Software Reset
4
165
Restore Factory Data
4 16 - Write Multiple Registers
40
2 4 Float Data
Write Parameter - Baud Rate (BT)
44
Write Parameter - Slave Address (DE)
48
Write Parameter - Check Mode (0ddP)
52
Write Parameter - Stop Bit (Stop)
60
Write Parameter - Float Format (FFT)