Sigma – UNC Controller Log Data Handling During Server Communication Failure

[Product_Support]

Issue

This article explains how a Sigma UNC controller manages log data when communication with the server is interrupted.

Product Line

Satchwell BAS & Sigma

Environment

• Satchwell Sigma - All versions
• UNC Controllers (V53 and ARM7 Series)

Cause

During normal operation, Sigma controllers log data and periodically upload it to the logging database. These uploads are managed by the UNC controller. If communication with the server fails, the controller temporarily stores the data in RAM until the connection is restored.

Resolution

When communication to the server is lost, the UNC controller follows a structured process to manage log data:

1. Alarm Buffer Initialization
   • After all files are downloaded, the Alarm Buffer is created.
   • It queues alarms and logs destined for the server.
   • Capacity: Up to 500 entries.
2. Logging Buffer Allocation
   • Memory is allocated to the Logging Buffer, which stores partially completed log data.
   • V53 Series Controllers (532, 496/596, IC1):
     Allocated 75% of remaining memory.
   • ARM7 Series Controllers (632, 696/796, IC3):
     Allocated 512 kB.
3. Logging Track Structure
   • The Logging Buffer uses 138-byte Tracks, with one Track per logged object.
   • Log records are added to the Track as events occur.
   • Once full, the Track is transferred to the Alarm Buffer.
4. Records per Track by Object Type

   Log Type	Object Type	Records per Track
   Timed	Analogue	25
   Timed	Digital	100
   Event	Analogue	14
   Event	Digital	32
   Alarm/Report (Log)	Any	28

5. Manual Log Retrieval
   • Partially full Tracks can be manually transferred to the Alarm Buffer via:
     Diagnostics > Options > Retrieve Logs
6. Autodial Connection Behavior
   • If an Autodial connection is configured, a call is initiated when:

     • Any non-opportunistic alarm or log is placed in the Alarm Buffer.