Danfoss Optyma Plus
Condensing unit controller for commercial refrigeration: pressures, temperatures, fan speed and alarms.
The Danfoss Optyma Plus is an air cooled condensing unit with its own controller that runs the compressor and condenser fan for cold rooms and display cases. This Modbus RTU template reads pressures, temperatures, superheat, fan speed, compressor capacity and alarms, and lets you write the main switch and suction setpoint from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 42, read and write
- Brand
- Danfoss
- Key readings
- Suction pressure · Condenser pressure · Discharge temperature · Superheat · Fan speed · Compressor capacity · Alarms
- Available commands
- Main switch · Suction setpoint · Night offset · Day and night times
- Compatible models
- Optyma Plus Controller 084B8080 · Optyma Plus Controller 084B8180 · Danfoss Optyma Plus condensing units with the Optyma Plus controller, SW 3.10 to 3.7x
- Last updated
Registers (42)
42 read, 7 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Superheat | K | Read | |||
| Suction Pressure Ps | bar | Read | |||
| Suction Temperature Ts | °C | Read | |||
| Suction Temperature S4 | °C | Read | |||
| Discharge Temperature S3 | °C | Read | |||
| Ambient Temperature S2 | °C | Read | |||
| Condenser Pressure Pc | bar | Read | |||
| Condensing Temperature Tc | °C | Read | |||
| Tc Reference | °C | Read | |||
| Compressor Capacity | % | Read | |||
| Fan Speed | % | Read | |||
| Auxiliary Temperature S5 | °C | Read | |||
| Auxiliary Temperature S6 | °C | Read | |||
| DI1 Status | Read | ||||
| Night Condition | Read | ||||
| DI2 Status | Read | ||||
| DI3 Status | Read | ||||
| Control State | Read | ||||
| Controller Error | Read | ||||
| Internal Controller Error | Read | ||||
| Pc Sensor Error | Read | ||||
| Ps Sensor Error | Read | ||||
| Ambient Sensor Error | Read | ||||
| Discharge Sensor Error | Read | ||||
| Suction Sensor Error | Read | ||||
| Auxiliary Sensor Error | Read | ||||
| Low Suction Pressure Alarm | Read | ||||
| Refrigerant Not Selected | Read | ||||
| Max Discharge Temperature Alarm | Read | ||||
| DI2 Alarm | Read | ||||
| High Pressure Alarm | Read | ||||
| Safety Input Alarm | Read | ||||
| Standby Mode | Read | ||||
| Condenser Air Flow Blocked | Read | ||||
| Drive Alarm | Read | ||||
| Main Switch | Read and write | ||||
| Night Offset | K | Read and write | |||
| Ts Reference | °C | Read and write | |||
| Day Start | h | Read and write | |||
| Night Start | h | Read and write | |||
| Clock Hours | h | Read and write | |||
| Clock Minutes | min | Read and write |
Loading registers…
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Show suction pressure, condensing temperature and discharge temperature of every condensing unit on one dashboard.
- Get an email when the high pressure, low suction pressure or max discharge temperature alarm turns on.
- Watch fan speed and compressor capacity over a year to spot fouled condensers before summer.
- Switch a unit off remotely with the main switch during maintenance on the cold room.
- Adjust the suction setpoint or night offset from ModbusCloud when the cold room use changes.
Installation
Wire the RS485 terminals of the Optyma Plus controller to the RS485 port of the ModbusCloud Gateway, with a 120 ohm resistor at both ends of the bus.
Give the controller a unique Modbus address and keep the bus at 19200 baud, 8 data bits, even parity, 1 stop bit.
In ModbusCloud, add a Modbus device (RTU) with that address and import this template.
Check that suction pressure, condenser pressure and ambient temperature show plausible values.
Set alarm rules on the alarm registers you want to be told about, such as high pressure and max discharge temperature.
Things to watch for
The controller does not answer on the bus. What should I check?
Use even parity and 1 stop bit, and check the address set on the controller. The controller detects 9600, 19200 or 38400 baud by itself, but only after a few requests at the new speed, so give it a moment after changing the master. Swap A and B if it still does not answer.
Why do pressures and temperatures look ten times too high?
Most readings are sent as whole numbers in tenths, so 52 means 5.2. The template applies that scale. The suction setpoint and the setting registers are whole numbers without a decimal.
How do I get notified of a unit fault?
Each alarm, such as high pressure, low suction pressure, max discharge temperature or a sensor error, has its own register that reads 1 while the alarm is active. Put an alarm rule on the ones that matter, for example equal to 1.
Is it safe to write the main switch and suction setpoint?
Main switch 0 stops the unit and -1 puts it in service mode, so write it only when you mean to stop refrigeration. Keep the suction setpoint within -30 to 10 and agree changes with whoever is responsible for the cold room.
Want to see how it works?
