¶ Overview
The program is designed to receive data from the RefControl device, which reads operating and performance parameters from refrigeration units and transmits them to the device.
The program was developed by Alexey Yakovchuk, engineer at Baltavtomatika LLC.
Contact information: support@baltgps.ru, baltgps.ru.
RefControl connects to the refrigeration unit via RS-232/CAN, and to the device via RS-485/RS-232.
The Complex Events program listens to the RS-485 (RS-232) interface, parses packets from RefControl, and writes the received values to "CE User Parameters".
¶ Downloads
Main:
Additional:
Program File
User Manual¶ List of Supported Units
- Carrier Vector 1550
- Carrier Vector 1850
- Thermo King SLX 200
The list of supported units is current as of the article publication date, 18.07.2026, and is continuously expanding.
For information about support for other refrigeration unit models, please contact the script developer at support@baltgps.ru
¶ Implementation
¶ General Logic
The program listens to the RS-485 (RS-232) interface and parses the data that RefControl receives from the refrigeration unit.
General data exchange scheme:
Carrier Vector 1550/1850 <-> RS-232/CAN <-> RefControl <-> RS-485/RS-232 <-> Device
¶ Main Parameters
- Supply air temperature
SAT. - Return air temperature
RAT. - Ambient air temperature
AAT. - Setpoint temperature
SPT. - Defrost termination temperature
DTT. - Engine temperature
ENCT. - Engine speed
ENRPM. - Charging voltage
BTYV. - Engine hours and total unit operating time.
- Number of startup cycles.
¶ Additional Parameters
-
High-speed operating hours
-
Total unit ON time
-
Operating hours (on standby power)
-
Compressor operating hours
-
Line 1 current (AC 1)
-
Line 2 current (AC 2)
-
Direct current (DC)
-
Evaporator outlet temperature (EVOT)
-
Condenser discharge temperature (CDT)
-
Compressor suction modulation valve (CSMV)
-
Evaporator valve (EVXV)
-
Decoding of non-standard parameters is also possible
If the refrigeration unit is switched off, some temperature parameters may be unavailable.
In this case, it is recommended to process the special value-128in the monitoring system as an indication that valid data is unavailable.
¶ Configuration
The attached object template for the Wialon monitoring system contains examples of sensor configuration for correct display of refrigeration unit parameters in the system.
¶ Connection
The RefControl device is powered from a 12/24 V circuit through a 1 A fuse. The connection points are similar to those used for the monitoring unit.
The recommended connection point to the Carrier Vector data line is the standard three-pin Delphi connector marked SLP A/B/C (Satcom), located under the refrigeration unit control module housing.
The exact pinout of the SLP A/B/C connector depends on the specific refrigeration unit model and controller version. During installation, use the RefControl connection instructions for Carrier Vector 1550/1850.
RefControl connection lines:
| Line | Purpose |
|---|---|
GND |
Common ground |
+12V |
Device power supply through a 1 A fuse |
RS-485 B |
Data line B to the Navtelecom terminal |
RS-485 A |
Data line A to the Navtelecom terminal |
RS-232 TX |
Data transmission to the refrigeration unit |
RS-232 RX |
Data reception from the refrigeration unit |
¶ In the Device Configuration
¶ On the "RS-232/RS-485" Tab
For the RS-485 interface, select:
| Setting | Value |
|---|---|
| Device | Complex Events (asynchronous) |
| Baud Rate | 9600 |
| Parity | None |
| Stop Bits | 1 |
¶ On the "Complex Events" Tab
- Enable the Complex Events function and write the configuration to the device.
- Reconnect to the device.
- Upload the program to the device
Article with an animation of the steps listed above
¶ In the Data Transmission Protocol
Configure transmission of "CE User Parameters" to the monitoring system:
All parameters must be transmitted as User-defined 4-byte parameters
| CE Parameter |
Linked Variable |
Description | Variable Type |
|---|---|---|---|
| 1 | en_ct | Engine temperature ENCT |
FLOAT |
| 2 | engine_rpm | Engine speed | U32 |
| 3 | bt_yv | Charging voltage BTYV |
FLOAT |
| 4 | en_hours_total | Total engine operating hours | U32 |
| 5 | en_hours_ext_pow | Operating hours on external power | U32 |
| 6 | on_hours_total | Total unit ON time | U32 |
| 7 | en_hours_h_speed | High-speed engine hours | U32 |
| 8 | startup_cycles | Number of startup cycles | U32 |
| 9 | sat_f | Supply air temperature SAT |
FLOAT |
| 10 | rat_f | Return air temperature RAT |
FLOAT |
| 11 | aat_f | Ambient air temperature AAT |
FLOAT |
| 12 | spt_f | Setpoint temperature SPT |
FLOAT |
| 13 | dtt_f | Defrost termination temperature DTT |
FLOAT |
| 14 | chip_id | Service device identifier | U32 |
| 15 | cpu_temperatur | Device CPU temperature | FLOAT |
When checking telemetry, 4-byte user parameters are recommended to be displayed as
floatfor floating-point values (temperatures, voltage), and asint/uintfor integer values.Show Example
To configure sensors in the Wialon monitoring system, you can use the attached template, which includes sensors, calculation expressions, and units of measurement for the main refrigeration unit parameters.