Simcom's SIM100 gsm modem problem

[tramp]

simcom modem reset problem

Hi,
I am using simcom's sim100 gsm modem.It get power on properly but not get register to network.what could be probable cause.

tramp

 

[eng_ahmed22]

simcom sim100 manual

hi
i have the same problem.
and more, it send "RDY" every 20 Sec
it seems to be RESET
how can i make it works???
plz Help
Bye

 

[pisoiu]

at+creg simcom

The GSM network registering procedure may generate a reset condition if your power supply has poor transitory response or if you use a bad antenna, with high VSWR. Make sure you use at least 100uF capacitor as closest as possible to the supply pins. Check with an oscilloscope the spikes generated when the modem transmits, it should not exceed 2-300mV.

/pisoiu

 

[MacroGroup]

at+cops=? sim300

I have a problem with SIM300 GSM module. SIM300 could not recognize some SIM cards. I supposes, that it is a new SIM cards with extended memory. Module can't get register to GSM network.

Example below for normal SIM cards:
------------------

+CREG: 2

RDY

+CFUN: 1

+CPIN: READY

+CREG: 1
at+cops?

+COPS: 0,0,"MTS"

OK
at+ccid

89701011600008009301

OK

------------------

And for not working SIM cards:
------------------

+CREG: 2

RDY

+CFUN: 1

+CREG: 0
at+ccid

00000000000000000000

OK
at+cops?

+COPS: 0

OK

------------------

From these examples we can see that SIM300 is pass to registered stage, but then it give message that it not registered. On the other hand this SIM card is working in GSM phone.

Dear pisoiu, could you please explain what the problem and how I can solve this problem?:?:

 

[pisoiu]

reset gsm modem simcom

I am sorry, I've never encountered this problem so far, so I don't know what is your problem.

/pisoiu