Danfoss AK-CC 350

Name: Danfoss AK-CC 350
Brand: Danfoss
SKU: 6e29fdcd-a453-475e-8c4b-5af45814b3bd

Controls temperature, defrost and fans in refrigerated display cabinets and cold rooms.

The Danfoss AK-CC 350 is a case and cold room controller that regulates temperature, defrost and fans in refrigerated display cabinets and cold rooms. This Modbus RTU template reads all temperatures, the controller state and every alarm, and lets you change the setpoint, alarm limits and defrost settings from ModbusCloud.

Protocol: Modbus RTU
Connection: RS485, 38400 baud
Registers: 118, read and write

Brand: Danfoss
Key readings: Thermostat air temperature · S3 and S4 air temperature · S5 evaporator temperature · HACCP temperature · Controller state · Alarm flags
Available commands: Temperature setpoint · Main switch · Defrost start · Alarm limits · Defrost schedule
Compatible models: AK-CC 350 (084B4165)
Last updated: 23 October 2026

Registers (118)

118 read, 85 write

Name	Unit	Access
Thermostat Air Temperature	°C	Read
S4 Air Temperature	°C	Read
S3 Air Temperature	°C	Read
S5 Temperature	°C	Read
Display Air Temperature	°C	Read
Alarm Air Temperature	°C	Read
Regulation Reference	°C	Read
HACCP Temperature	°C	Read
HACCP Peak Temperature	°C	Read
Controller State		Read
Defrost State		Read
DI1 Status		Read
DI2 Status		Read
Night Condition		Read
Controller Error		Read
Controller Error Alarm		Read
Clock Error Alarm		Read
S3 Sensor Error		Read
S4 Sensor Error		Read
S5 Sensor Error		Read
High Temperature Alarm		Read
Low Temperature Alarm		Read
HACCP Alarm		Read
Door Alarm		Read
DI1 Alarm		Read
DI2 Alarm		Read
Max Defrost Time Alarm		Read
Max Hold Time Alarm		Read
Case Cleaning Alarm		Read
Standby Mode Alarm		Read
Main Switch		Read and write
Temperature Setpoint	°C	Read and write
Defrost Start		Read and write
Reset Alarm		Read and write
Forced Cooling		Read and write
Night Setback		Read and write
Thermostat Differential	K	Read and write
Max Setpoint Limit	°C	Read and write
Min Setpoint Limit	°C	Read and write
Display S4 Weighting	%	Read and write
Display Temperature Adjustment	K	Read and write
Temperature Unit		Read and write
S4 Sensor Correction	K	Read and write
S3 Sensor Correction	K	Read and write
Night Setback Offset	K	Read and write
Thermostat S4 Weighting	%	Read and write
Reference Offset Active		Read and write
Reference Offset	K	Read and write
Compressor Min On Time	min	Read and write
Compressor Min Off Time	min	Read and write
Compressor Relay NC Function		Read and write
External Relays		Read and write
Defrost Method		Read and write
Defrost Stop Temperature	°C	Read and write
Defrost Interval	h	Read and write
Max Defrost Duration	min	Read and write
Defrost Start Delay At Power Up	min	Read and write
Drip Off Time	min	Read and write
Fan Start Delay After Defrost	min	Read and write
Fan Start Temperature	°C	Read and write
Fan During Defrost		Read and write
Defrost Stop Sensor		Read and write
Pump Down Delay	min	Read and write
Max Refrigeration Time Between Defrosts	h	Read and write
Defrost On Demand S5 Variation	K	Read and write
Hold After Defrost		Read and write
Max Hold Time After Coordinated Defrost	min	Read and write
Defrost 1 Start Hour	h	Read and write
Defrost 1 Start Minute	min	Read and write
Defrost 2 Start Hour	h	Read and write
Defrost 2 Start Minute	min	Read and write
Defrost 3 Start Hour	h	Read and write
Defrost 3 Start Minute	min	Read and write
Defrost 4 Start Hour	h	Read and write
Defrost 4 Start Minute	min	Read and write
Defrost 5 Start Hour	h	Read and write
Defrost 5 Start Minute	min	Read and write
Defrost 6 Start Hour	h	Read and write
Defrost 6 Start Minute	min	Read and write
Fan Stop At Compressor Cutout		Read and write
Fan Stop Delay	min	Read and write
Fan Stop Temperature	°C	Read and write
Temperature Alarm Delay	min	Read and write
Door Alarm Delay	min	Read and write
Alarm Delay After Defrost	min	Read and write
High Alarm Limit	°C	Read and write
Low Alarm Limit	°C	Read and write
DI1 Alarm Delay	min	Read and write
DI2 Alarm Delay	min	Read and write
Alarm S4 Weighting	%	Read and write
HACCP Sensor Selection		Read and write
HACCP Alarm Limit	°C	Read and write
HACCP Alarm Delay	min	Read and write
HACCP S4 Weighting	%	Read and write
Output Delay At Start Up	s	Read and write
DI1 Configuration		Read and write
Sensor Type		Read and write
DI2 Configuration		Read and write
Case Cleaning		Read and write
Compressor Relay		Read and write
Defrost Relay		Read and write
Fan Relay		Read and write
Alarm Relay		Read and write
Light Configuration		Read and write
Light Remote Switch		Read and write
Light Relay		Read and write
Rail Heat On Time Day	%	Read and write
Rail Heat On Time Night	%	Read and write
Rail Heat Period	min	Read and write
Rail Heat Relay		Read and write
Drain Delay	min	Read and write
Suction Line Valve Relay		Read and write
Compressor 2 Cut In Delay	s	Read and write
Compressor 2 Relay		Read and write
Heat Function Start Offset	K	Read and write
Application Mode		Read
Module Software Version		Read
Transceiver Type		Read

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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 the thermostat air temperature of every cabinet in one dashboard and keep a year of history as evidence for food safety checks.
Send an email when the high or low temperature alarm flag goes to 1, or when a sensor error appears.
Alert when the HACCP temperature passes its limit, separately from the normal temperature alarm.
Check from the history whether defrosts start on schedule and how long the cabinet stays in each controller state.
Adjust the setpoint or alarm limits of a cold room remotely after a change in the stored product.

Installation

Connect the Disp./MODBUS terminals A+ and B- of the controller to the RS485 port of the ModbusCloud Gateway, with a 120 ohm termination at the end of the bus.
Set a unique network address in parameter o03 (1 to 240) on each controller.
In ModbusCloud, add a Modbus device with that address, 38400 baud, 8 data bits, even parity and 1 stop bit, and import this template.
Check that the thermostat air temperature and the controller state show plausible values.
If nothing answers, try 19200 or 9600 baud and swap A+ and B- once.

Things to watch for

The controller does not answer at all. What should I check?

Check that o03 holds an address other than 0, that the wires go to the Disp./MODBUS terminals and not the LON RS485 terminals, and that A+ and B- are not swapped. Danfoss does not publish the serial settings for this controller; start at 38400 baud 8E1 and try 19200 and 9600 if it stays silent.

Why do I read 1200 on the S3 or S5 temperature?

Temperatures come in tenths, so the template shows 120.0. A fixed high value like this usually means the sensor is not connected or not used in the selected application. The matching sensor error flag tells you whether the controller sees a fault.

Writing a setting has no effect. Why?

Some settings, such as the defrost method and the input configuration, can only change while the main switch stops regulation (0). Relay registers only switch in manual service (main switch -1). Set the main switch back to 1 afterwards, otherwise the cabinet stops cooling.

Some registers return errors or zero. Is the template wrong?

The controller has ten applications and not every function exists in each one: light, rail heat, a second compressor and the suction line valve only appear in some. Application Mode shows which one is active, and registers for other applications can stay empty.

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