Support request for GSM modem by email to me
I have hooked up my GSM modem to my PC and the SIM is registered on the network. But, I can not get the modem to respond to AT commands. I wonder if it needs a null modem on the rs232? From my terminal I see this….
AT command problem with GSM modem
As you can see it echos back in red, but does not give the response from the modem I would expect. I think it is something simple, but cant figure what is wrong.
Answer on GSM modem support request
- You do not need a null modem cable
- Does your PC have a RS232 or do you use a USB to RS232 converter.
- The first command I use always is “AT” and the answer will be “OK”.
- You use “ATT” instead of “AT”.
- The answers are the echo, but not the answer of the GSM modem. I have no idea which piece of hardware sent the echo. On “ATT” to the GSM modem you shall get “Error”, because it is a wrong command and on “AT” you can expect “OK”. For some reasons your and my GSM modem answer on “ATT” with “OK”.
- Worst case the AT will be send to the landline modem in your laptop.
- With AT+CREG you will detect if it your landline modem or a cellular modem.
- The landline will answer with “Error” and the cellular modem will give a useful answer. The answer is described in the manual.