intermittent problem with receiving audio data from PLS8 | Telit Cinterion IoT Developer Community

Hi,

I hope someone can help with the intermittent problem i have with a PLS8-E

I am using the audio interface in PCM mode to send and receive audio.
sometimes when a call is made to the PLS8 there is no audio data produced from the PLS8
The audio data going into the PLS8 is forwarded without fail to the receiving phone.
If the call is dropped and made again there is a good chance that both directions of audio work fine.
The problem can keep happening. So far i have only seen this error occur when a call is made to the PLS8 and sometimes it occurs after bootup and sometimes after many calls.

When the error occurred i kept the call active and configured the audio path for loopback using ^SCFG: "Audio/Loop","1" and as expected the audio being sent into the PLS8 was looped back thus proving the audio interface was working but for some reason i cannot receive data from the network.

my configuration for the audio interface is PCM, master, long frame, BCLK=4096, sample rate =16KHz. I require PCM as i need the clock there all the time and not just when a call is present.
AT^SAIC=1,1,1,3,0,1,0,1

i am setting the echco canceller and noise suppressor to transparent operation
AT^SNFS=6

I monitor the output data port (from the PLS8)  using an oscilloscope to see if there is any activity on the port.  What i notice when it fails is that the data is there momentarily then disappears and the data output is then low.
It is as though something has reconfigured after the call has been answered.

In my desperation to figure out what is going on i have tried different SAIC configurations including I2S but still the error can occur.

my other configuration is

AT
AT^SCFG="MEopMode/PwrSave","disabled"
AT^SCFG="URC/DstIfc","mdm"

If anyone can help that would be much appreciated.
Thanks

Alan

just to be thorough, here is my SCFG configuration

tx AT^SCFG?
rx
rx ^SCFG: "Audio/Ecfg","0"
rx ^SCFG: "Audio/Loop","0"
rx ^SCFG: "Audio/SvTone","0"
rx ^SCFG: "Call/ECC","0"
rx ^SCFG: "Call/Speech/Codec","0"
rx ^SCFG: "Call/VoLTE/Codec","0"
rx ^SCFG: "GPRS/Auth","2"
rx ^SCFG: "GPRS/AutoAttach","enabled"
rx ^SCFG: "MEopMode/CFUN","1","1"
rx ^SCFG: "MEopMode/DTM/Mode","1"
rx ^SCFG: "MEopMode/ExpectDTR","current","acm1","acm2","acm3","acm4","rmnet0","rmnet1","asc0"
rx ^SCFG: "MEopMode/ExpectDTR","powerup","acm1","acm2","acm3","acm4","rmnet0","rmnet1","asc0"
rx ^SCFG: "MEopMode/IMS","1","mmtel","smsip"
rx ^SCFG: "MEopMode/NonBlock/Cops","0"
rx ^SCFG: "MEopMode/PingRsp","1"
rx ^SCFG: "MEopMode/PowerMgmt/LCI","disabled"
rx ^SCFG: "MEopMode/Prov/AutoSelect","on"
rx ^SCFG: "MEopMode/Prov/Cfg","fallback*"
rx ^SCFG: "MEopMode/PwrSave","disabled","0","50"
rx ^SCFG: "MEopMode/SRPOM","0"
rx ^SCFG: "MEShutdown/OnIgnition","off"
rx ^SCFG: "MEShutdown/Timer","off"
rx ^SCFG: "Misc/CId",""
rx ^SCFG: "Radio/Band","2928787"
rx ^SCFG: "Radio/CNS","0"
rx ^SCFG: "Radio/Mtpl","0"
rx ^SCFG: "Radio/OutputPowerReduction","4"
rx ^SCFG: "RemoteWakeUp/Event/ASC","none"
rx ^SCFG: "RemoteWakeUp/Event/URC","none"
rx ^SCFG: "RemoteWakeUp/Event/USB","none"
rx ^SCFG: "RemoteWakeUp/Ports","current","acm1","acm2","acm3","acm4","rmnet0","rmnet1","asc0"
rx ^SCFG: "RemoteWakeUp/Ports","powerup","acm1","acm2","acm3","acm4","rmnet0","rmnet1","asc0"
rx ^SCFG: "RemoteWakeUp/Pulse","10"
rx ^SCFG: "SIM/CS","SIM_1"
rx ^SCFG: "SIM/Retry","on"
rx ^SCFG: "SMS/4GPref","IMS"
rx ^SCFG: "SMS/AutoAck","0"
rx ^SCFG: "SMS/Retrm",5
rx ^SCFG: "Tcp/IPv6Priv","1"
rx ^SCFG: "Tcp/Loop","disabled"
rx ^SCFG: "Tcp/MR","10"
rx ^SCFG: "Tcp/OT","6000"
rx ^SCFG: "Tcp/TLS/Version","MIN","***"
rx ^SCFG: "Tcp/UnreachRsp","1"
rx ^SCFG: "Tcp/WithURCs","on"
rx ^SCFG: "URC/DstIfc","mdm"
rx ^SCFG: "URC/Ringline","local"
rx ^SCFG: "URC/Ringline/ActiveTime","2"
rx ^SCFG: "URC/Ringline/SelWUrc","all"