Modem is a built-in module.
Devices are sealed (I can’t look inside) and mostly on warranty, but problem is too frequent. We replaced more than 50 devices. Warranty is expires soon & we need to solve that problem without supplier - this would become OUR problem, not their.
Device has it’s own processor, i2c, rs232 & can communicate with integrated modem module.
I can program main device processor, but have access to modem via internal rs232 only.
The problem is: when it is hard to register in the gsm network, modem can stop answer to command +CREG? or +CFUN=1, usualy that is not fatal. After DTR on/off and some atz like commands it answers again. But sometimes after +CFUN=1 it stops answer forever. Also it can stop answer forever during standart start-up or shutting down, probably under the same hard network conditions. And this is a problem.
They not interested to solve that problem. AFAIU - too local problem. We still trying this way, but it takes too much time and no confidence in success.
Their common position - “What did you do with modem?! We have no such a problem!”
What can I say?
I have logs, logs show problem with modem.
We have other devices of other manufacturer, or other GSM modem, connected to problem device (it has RS232), we use the same i/o protocol & have no such a problem. So we consider - this is a problem of modem software. I’ve thought this can be a a well-known problem for Wavecom and there is a software upgrade for this model.
Take a look - I think I can’t do something wrong with modem by fallowing commands:
SET_DTR:
SET_DTR:
EMPTY_READ: 2 times (no income data found during timeout)
WRITE: [16]AT&FE0V1+CREG=0 (send command to modem)
EMPTY_READ: 49 times
READ: [6] (recieved from modem)
OK
WRITE: [10]AT+CMEE=1
EMPTY_READ: 1 times
READ: [6]
OK
WRITE: [10]AT+WAIP=1
EMPTY_READ: 1 times
READ: [6]
OK
WRITE: [5]AT&W
EMPTY_READ: 15 times
READ: [6]
OK
WRITE: [10]AT+CFUN=1 !!! (this is the last fatal command, but previous +CFUN=1 were successfull. What can I do wrong here or later?)
EMPTY_READ: 741 times (5 seconds time-out)
CLEAR_DTR:
EMPTY_READ: 851 times
SET_DTR:
module restart
SET_DTR:
EMPTY_READ: 2 times
WRITE: [16]AT&FE0V1+CREG=0
EMPTY_READ: 4337 times
WRITE: [16]AT&FE0V1+CREG=0
EMPTY_READ: 870 times
WRITE: [16]AT&FE0V1+CREG=0
…
If I do not use +WAIP=1, &F, &W and +CFUN=1, modem fatally fails on start up or shutting down - I can’t guess.
Before fatal command we can find non-fatal same problems with network registration:
…
WRITE: [16]AT&FE0V1+CREG=0
EMPTY_READ: 91 times
READ: [6]
OK
WRITE: [10]AT+CMEE=1
EMPTY_READ: 344 times
READ: [6]
OK
WRITE: [9]AT+CREG?
EMPTY_READ: 1 times
READ: [8]
+CREG:
READ: [8] 0,0
READ: [4]OK
EMPTY_READ: 2211 times
WRITE: [9]AT+CREG?
EMPTY_READ: 3 times
READ: [8]
+CREG:
READ: [8] 0,2
READ: [4]OK
EMPTY_READ: 2205 times
WRITE: [9]AT+CREG? (oops! no answer! but later we will get it)
EMPTY_READ: 2158 times
WRITE: [16]AT&FE0V1+CREG=0
EMPTY_READ: 4342 times
WRITE: [16]AT&FE0V1+CREG=0
(still no answer! but later we will get it)
…