Issue
This article clarifies what a Sigma UNC controller does when logging is going on and comms to the server has been lost.
Environment
Sigma - All versions
Cause
When a sigma controller is logging, during normal operation the data is uploaded to the logging database at various intervals. These uploads are generally controlled by the UNC controller. If comms to the server is lost then the data is stored in RAM until comms to the server is re-established. The resolution details how this happens and what the limitations are.
Resolution
In the controller, after all files have been downloaded, the Alarm buffer is created. The Alarm buffer holds the queue of alarms and logs being sent to the server and can hold up to 500 entries.
Then memory is allocated to the Logging buffer which stores partially complete logging data. It is allocated memory as follows:
|
First series controllers (532, 496/596, IC1): |
75% of the remaining memory |
|
ARM 7 series controllers (632, 696/796, IC3): |
512kB |
The Logging buffer contains 138-byte Tracks with one Track for each logged object. Log records are added to the Track as they occur and the Track is transferred to the Alarm buffer when full.
The maximum number of log records that a Track contains depends on the type of object and the type of log as follows:
|
Operation |
Object Type |
Records per track |
|---|---|---|
|
Timed |
Analogue |
25 |
|
Timed |
Digital |
100 |
|
Event |
Analogue |
14 |
|
Event |
Digital |
32 |
|
Alarm/report (as a log) |
Any |
28 |
Partially full Tracks can be moved to the Alarm buffer (and thus automatically to the server) by selecting Diagnostics > Options > Retrieve Logs.
Where an Autodial connection is used, a telephone call is initiated when any alarm (non opportunistic) or log is placed in the Alarm buffer.
