PLS62W problems changing baud | Telit Cinterion IoT Developer Community
September 14, 2020 - 3:23am, 1362 views
We are seeing a minor issue when changing baud rates on our PLS62W modems. The example below shows the modem initially running at 3000000 baud. We detect the modem by sending AT and receiving OK, and then attempt to set the baud to 921600. The modem returns OK, so we then change our baud rate to 921600 and send AT at the new rate. However, we receive no ack from the modem after three tries. Switching back to 3000000 baud, we see the modem is still responding at this original rate. Retrying the baud rate switch command finally forces the modem to the new baud rate
[BAUD = 3000000]
AT
OK
AT+IPR=921600
OK
[BAUD = 921600]
AT
AT
AT
[BAUD = 3000000]
AT
OK
AT+IPR=921600
[no response]
[BAUD = 921600]
ATE1
OK
Modem info:
Cinterion
PLS62-W
REVISION 02.010
A-REVISION 01.000.05
Hello,
The default baudrate set in the factory is 115200 so I suppose that 3000000 was set by you. I have the same module but have never noticed such an issue. Could you write if you observe this on many modules and if it happens only while changing from 3000000 or it does not depend on the baudrate? Is it easily reproducible? Is AT+IPR sent as standalone command or concatenated with other commands? Please also note that the command only applies for the interface on which it is sent.
Regards,
Bartłomiej
Hi Bartłomiej,
We have tried several baud rates, and the same behaviour seems to occur. In this case we had ended up at 3000000 baud on a previous test, which is why the test started at that baud. With this particular modem the issue happens every time I try changing baud. I will need to do more tests to try different modems.
But, I have worked around the issue by sending an "AT" after the baud change. I don't always get an OK response to this command, but it seems to force the change. For example:
[BAUD = 921600]
AT
OK
AT+IPR=230400
OK
AT
OK (not always received)
[BAUD = 230400]
AT
OK
Hello,
This is quite strange. I tried with my module but did not see such a behavior. Please check with some other module. Please also check the module configuration - AT^SCFG? and AT&V outputs - maybe it's somehow related.
Regards,
Bartłomiej
Hello,
I don't think we are using any non-standard settings. I wonder if the modem waits to see some activity on the comm port before changing the baud. So it might depend which baud rates are being used. Have you tried starting on 3000000 baud and moving down to 500000?
Here are our settings:
AT&V
ACTIVE PROFILE:
E1 Q0 V1 &C1 &D2 &S1 \Q3
S0:000 S3:013 S4:010 S5:008 S6:000 S7:060 S8:000 S10:002
+CMGF: 0
+CNMI: 1,0,0,0,0
+ICF: 3
+IPR: 500000
+CMEE: 2
+CSMS: 0,1,1,1
+CREG: 2,0
+CEREG: 2,0
+COPS: 2
+CGSMS: 1
OK
AT^SCFG?
^SCFG: "GPRS/AutoAttach","enabled"
^SCFG: "Gpio/mode/ASC1","std"
^SCFG: "Gpio/mode/DCD0","gpio"
^SCFG: "Gpio/mode/DSR0","std"
^SCFG: "Gpio/mode/DTR0","std"
^SCFG: "Gpio/mode/FSR","std"
^SCFG: "Gpio/mode/HWAKEUP","rsv"
^SCFG: "Gpio/mode/PULSE","gpio"
^SCFG: "Gpio/mode/PWM","gpio"
^SCFG: "Gpio/mode/RING0","gpio"
^SCFG: "Gpio/mode/SPI","rsv"
^SCFG: "Gpio/mode/SYNC","gpio"
^SCFG: "Ident/Manufacturer","Cinterion"
^SCFG: "Ident/Product","PLS62-W"
^SCFG: "MEShutdown/Fso","1"
^SCFG: "MEShutdown/sVsup/threshold","0","0"
^SCFG: "MEopMode/CFUN","0","1"
^SCFG: "MEopMode/CregRoam","0"
^SCFG: "MEopMode/ExpectDTR","current"
^SCFG: "MEopMode/ExpectDTR","powerup"
^SCFG: "MEopMode/Prov/AutoSelect","off"
^SCFG: "MEopMode/Prov/Cfg","attus"
^SCFG: "MEopMode/RingOnData","off"
^SCFG: "MEopMode/SoR","off"
^SCFG: "MeOpMode/SRPOM","0"
^SCFG: "Radio/Band/2G","0x00000074"
^SCFG: "Radio/Band/3G","0x0004019B"
^SCFG: "Radio/Band/4G","0x080E08DF"
^SCFG: "Radio/Mtpl/2G","0"
^SCFG: "Radio/Mtpl/3G","0"
^SCFG: "Radio/Mtpl/4G","0"
^SCFG: "Radio/OutputPowerReduction","4"
^SCFG: "RemoteWakeUp/Ports","current"
^SCFG: "RemoteWakeUp/Ports","powerup"
^SCFG: "Serial/Ifc","0"
^SCFG: "Serial/Interface/Allocation","1","1"
^SCFG: "Serial/USB/DDD","0","0","0409","1E2D","005B","Cinterion Wireless Modules","PLSx",""
^SCFG: "Tcp/IRT","3"
^SCFG: "Tcp/MR","10"
^SCFG: "Tcp/OT","6000"
^SCFG: "Tcp/WithURCs","on"
^SCFG: "Trace/Syslog/OTAP","0"
^SCFG: "Urc/Ringline","local"
^SCFG: "Urc/Ringline/ActiveTime","2"
^SCFG: "Userware/Autostart","1"
^SCFG: "Userware/Autostart/Delay","0"
^SCFG: "Userware/DebugInterface","0.0.0.0","0.0.0.0","0"
^SCFG: "Userware/DebugMode","on"
^SCFG: "Userware/Passwd",
^SCFG: "Userware/Stdout","null",,,,"off"
^SCFG: "Userware/Watchdog","0"
OK
Hello,
The module should not wait for any activity. It should change the baudrate immediately. If you are fast enough you may be able to send something before it switches like you described before.
The settings seem to be quite standard.
Unfortunately I can't try 3000000 because I don't have the hardware supporting it. I think you should verify this with some other module of the same type.
Regards,
Bartłomiej