we *sometimes* get an error: "at^siso=1 OK ^SIS: 1,0,16,"No buffer space available".
Strangely enough, this happens already at the first connection we create and the error then is repeated for every following connection we try to create.
This seems to be socket connection error so it should be related to socket connections buffer. It could for example happen when there is too many connections or the connections are opened and closed very fast.
But according to your description there should not be buffer space problems as it's the first connection.
Have you tried to diagnose the network connection, signal quality etc. when this problem happens?
Is this error repeated until the reboot or until the device is moved to another place or maybe you have any other observation?
What is the module type and firmware version (ATI1 command)?
- Signal quality seems bad-medium quality: other test runs give no problems others fail with timeouts.
Could it be that in the PLS8-E the firmware consumes buffers in trying to retransmit data?
- ATI1, Cinterion, PLS8-E, REVISION 03.017, A-REVISION 01.000.0
- After power cycling the problem it gone and the next test we ran worked again
So maybe it is somehow indirectly related to the network quality. Have you tried AT+CEER command to see any error reports?
Another test might be to manually deregister from the network and register again instead of power cycling when the problem occurs. Then you could check if that helps or not.
The firmware that you have is also not the latest for revision 3, so you could try to test with the current version.
I tried to deregister and *********** using AT+COPS=2 and then an AT+COPS=0, but the error occurred again yesterday, again at SISO. Note that it is *very* sporadic. It happens maybe once a month where it is often active.
Note that our test setup is such that every day and night, every 15 minutes we do some transmission tests. Before and after each transmission the modem is powered down requiring it to *********** each time anyways. Once a month, we then see this error. The error then goes away after a few reboots of the modem.
Would it be possible to paste a log with timestamps from the module booting, where the connection is configured, executed and then the problem happens?
If sometimes a few reboots of the module are needed, maybe there is some problem with network quality at the time when this occurs or there are some issues on the server side which contribute to this problem.
It might be hard to debug until there is a way to reproduce this easily.
I can also send you the latest firmware so you could verify if the behavior is the same.