Page 18
– Bulletin 100-50-5.2
APPENDIX K - MODBUS Memory Map (continued)
REGISTER ADDRESS/DESCRIPTION
RANGE
Read Holding Register
(0x03)
20. Pressure Calibration Offset
-5 to 5 PSI (-0.34 to 0.34 Bar)
21. Suction Temperature Calibration Offset
-5 to 5°F (-2.8 to 2.8°C)
22. Liquid Outlet Temperature Calibration Offset
-5 to 5°F (-2.8 to 2.8°C)
23. Liquid Inlet Temperature Calibration Offset
-5 to 5°F (-2.8 to 2.8°C)
24. Auxiliary Temperature Calibration Offset
-5 to 5°F (-2.8 to 2.8°C)
25. Temperature Sensor Type
0 = 3K
1 = 2K
26. Low Superheat Integral
1-255, Default is 10
Read Input
Registers (0x04)
0. Controller FW Rev Level
0 to 65,535
1. Liquid Outlet Temperature
-60 to 150°F (-51.1 to 65.6°C)
2. Superheat
0 to 165°F (0 to 91.6°C)
3. Suction Pressure
Depends on Pressure Sensor Range
and Type
(-15 to 500 PSI, -1.01 to 34.47 Bar)
Maximum Range
4. Saturation Temperature
-60 to 150°F (-51.1 to 65.6°C)
5. Suction Temperature
-60 to 125°F (-51.1 to 65.6°C)
6. Valve Position (% of Max. Stroke)
0 to 1000 (0 to 100.0%) Open
7. Liquid Inlet Temperature
-60 to 125°F (-51.1 to 65.6°C)
8. Auxiliary Temperature
-60 to 125°F (-51.1 to 65.6°C)
9. System State
If Bit set then mode is active:
Bit 0 = Setup Mode
Bit 1 = Off Cycle
Bit 2 = Cooling Cycle
Bit 3 = Pump-down Cycle
Bit 4 = Manual Valve Override Mode
10. Alarm Status
If Bit set then alarm is active:
Bit 0 = Pressure Sensor Failure
Alarm
Bit 1 = Suction Temperature Sensor
Failure Alarm
Bit 2 = Liquid Outlet Temperature
Sensor Failure Alarm
Bit 3 = Low Superheat Alarm
Write Single Coil
(0x05)
0. Manual Valve Enabled Flag
0 = Disabled, 1 = Enabled
The other coils are read-only.
Write Single Register
(0x06)
Same as above.
The max number of registers written
at a time is 1.
The limits are listed under ‘Read
Holding Register.’
