Issue
Unable to establish communication between a Sigma laptop and a Sigma controller via the RS-232 connection (Diagnostic Port SK1).
Product Line
Satchwell BAS & SigmaEnvironment
Sigma UNC Controller
Cause
Incorrect configuration settings.
Resolution
Use the following checklist to verify and correct the configuration:
On the Main Sigma Server
- ✅ Create a Service Server in the main Sigma server.
- ✅ Ensure Att.set files are downloaded to the controllers.
On the Laptop
- ✅ Edit the configuration file located at
C:\\Sigma\\Data\\Sigma.ini:- Set
RS232 = 1 - Set
Commport = 1,Baudrate = 9600
⚠️ Note: Ensure the BAS Integrator is disabled, as it defaults to Comm Port 1.
- Set
- ✅ Set the Laptop Server Number to match the Service Server Number configured in the main server.
(Navigate to: System Setup → General → Server Details) - ✅ Restart the Sigma Server on the laptop.
Software Version Considerations
- If using Sigma 4.05 build 3.42.34, a Hotfix is required to enable serial communications.
👉 Download Hotfix 3.42.46 - Later Sigma releases do not require this hotfix.
Hardware Check
- ✅ Confirm that the RS-232 cable wiring is correct and not damaged.
