RKI Instruments 65-2619RK-HC-04 - Manual (Page 45)

65-2619RK-HC-04 M2 Transmitter Operator’s Manual 40
Supported Modbus Functions
The M2 supports Function Code 03: Read Holding Registers and Function Code 16: Write
Registers. The register assignments detailed below were implemented in M2 firmware
version 5.0. Please see revision B of the M2 manual if you have an M2 with a firmware
version previous to 5.0.
WARNING: Do not attempt to use registers according to the instructions below with
units that have firmware versions previous to 5.0. For the Modbus register
assignments of M2s with firmware previous to 5.0, see revision B of the
M2 Operator’s Manual. The firmware version is shown on the
Information Screen described on page 16.
Function Code 03: Read Holding Registers
There are a total of 40 registers available to be read via this Function Code.
Registers 1 - 2
The format (bit & field assignments) for registers 1 - 2 is shown below in Table 10 -
Table 11.
Table 10: Register 1, Numerical Reading with Sign & Decimal Point Bit & Field Assignments
Bit(s) Value & Field
[15] Sign of Reading
0 = Positive
1 = Negative
[14:13] Format of Reading
0 = XXX (no decimal point)
1 = XX.X
2 = X.XX
3 = .XXX
[12:0] Numerical value of display reading (8000 max)
Table 11: Register 2, Operating State, Alarms & Relays Bit & Field Assignments
Bit(s) Value
[15:12] Operating State
0 = Undefined
1 = Initialization
2 = Normal
3 = Warm-up
4 = Fail
5 = Calibration
6 = Post-Calibration
7 = Low Power
8 = Setup