Danfoss Optyma iCO2 Gateway
CO2 condensing unit gateway: pressures, temperatures, valve openings and alarms.
The Danfoss Optyma iCO2 is a CO2 condensing unit for cold rooms and display cases, and its gateway makes the unit readable over Modbus RTU. This template reads pressures, temperatures, valve openings, 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
- 58, read and write
- Brand
- Danfoss
- Key readings
- High pressure · Receiver pressure · Suction pressure · Gas cooler outlet temperature · Discharge temperature · Compressor capacity · Alarms
- Available commands
- Main switch · Suction setpoint · Night offset · Day and night times
- Compatible models
- OP-MPAM005 · OP-MPAM015 · Danfoss Optyma iCO2 CO2 condensing units 4.6 kW MT and 20 kW MT / 10 kW LT with the iCO2 gateway, SW 1.0x
- Last updated
Registers (58)
58 read, 7 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Main Switch | Read and write | ||||
| Night Condition | Read | ||||
| Operation Condition | Read | ||||
| Suction Setpoint Ts Ref | °C | Read and write | |||
| Reference | °C | Read | |||
| Night Offset | K | Read and write | |||
| Fan Speed | % | Read | |||
| Day Start Hour | h | Read and write | |||
| Night Start Hour | h | Read and write | |||
| Clock Hours | h | Read and write | |||
| Clock Minutes | min | Read and write | |||
| CDU Software Version | Read | ||||
| High Pressure Pc | bar | Read | |||
| DI1 Status | Read | ||||
| Superheat | K | Read | |||
| DI2 Status | Read | ||||
| Compressor Capacity | % | Read | |||
| Alarm Relay | Read | ||||
| Gas Cooler Outlet Temperature | °C | Read | |||
| Receiver Outlet Temperature | °C | Read | |||
| Receiver Pressure | bar | Read | |||
| Receiver Temperature Trec | °C | Read | |||
| Condensing Temperature Tc | °C | Read | |||
| Suction Pressure Po | bar | Read | |||
| Evaporating Temperature To | °C | Read | |||
| Ambient Temperature | °C | Read | |||
| Discharge Temperature | °C | Read | |||
| Suction Temperature | °C | Read | |||
| Dynamic LP Off | °C | Read | |||
| Dynamic LP On | °C | Read | |||
| Gateway Firmware Version | Read | ||||
| Gateway Firmware Version (Danfoss format) | Read | ||||
| High Pressure Valve Opening | % | Read | |||
| Receiver Pressure Valve Opening | % | Read | |||
| Summary Alarm | Read | ||||
| Control State | Read | ||||
| Gas Cooler Out Sensor Error | Read | ||||
| Ambient Sensor Error | Read | ||||
| Discharge Sensor Error | Read | ||||
| Suction Temperature Sensor Error | Read | ||||
| Suction Pressure Sensor Error | Read | ||||
| Receiver Out Sensor Error | Read | ||||
| Receiver Pressure Sensor Error | Read | ||||
| Low Pressure Alarm | Read | ||||
| High Pressure Alarm | Read | ||||
| Gas Cooler Fan Alarm | Read | ||||
| Standby Mode Alarm | Read | ||||
| Gas Cooler Pressure Sensor Error | Read | ||||
| High Receiver Pressure Alarm | Read | ||||
| Max Discharge Temperature Alarm | Read | ||||
| Safety Alarm | Read | ||||
| Drive Alarm H23 | Read | ||||
| Drive Alarm H24 | Read | ||||
| Drive Alarm H25 | Read | ||||
| Drive Alarm H26 | Read | ||||
| Drive Alarm H28 | Read | ||||
| Drive Alarm H29 | Read | ||||
| MMILDS Communication Error | Read |
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 high pressure, receiver pressure and gas cooler outlet temperature of every CO2 unit on one dashboard.
- Get an email when the high pressure, high receiver pressure or max discharge temperature alarm turns on.
- Follow the high pressure valve opening and fan speed through a hot summer to see when the gas cooler reaches its limit.
- Switch a unit to standby 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 iCO2 gateway to the RS485 port of the ModbusCloud Gateway, with a 120 ohm resistor at both ends of the bus.
Set a unique slave address with parameter o03 on the MMILDS display and set the bus to 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 high pressure, suction 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 high receiver pressure.
Things to watch for
The gateway does not answer on the bus. What should I check?
Use even parity and 1 stop bit, and check the address set with o03 on the MMILDS display. The gateway switches between 19200 and 38400 baud by itself. Swap A and B if it still does not answer.
Why do pressures and temperatures look ten times too high?
Values with one decimal are sent multiplied by 10, so 127 means 12.7. The template applies that scale. Fan speed, compressor capacity and valve openings are whole percentages.
How do I get notified of a unit fault?
Each alarm, such as high pressure, low pressure, high receiver pressure, gas cooler fan or a sensor error, has its own register that reads 1 while active. The summary alarm reads 1 when any alarm is present. Put an alarm rule on the ones that matter.
Is it safe to write the main switch and suction setpoint?
Main switch 0 puts the unit in standby, so write it only when you mean to stop refrigeration; 2 starts vacuum mode for service. Keep the suction setpoint within -20 to 10 °C and agree changes with whoever is responsible for the cold room.
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