AT Commands how to check and respond on return messages from modem

General
1

I have a SIM7000E hat connected to my Raspberry. I want to connect the Raspberry to the internet using the SIM7000E hat.

I have manged to get everything working and get responses from the modem when i send the AT commands. I am however unable to get a way to resend the at command if the modem does not return an "OK" and/or respond with an error.

The modem returns two strings when i send the the at command like in the example below.

image

How can i resend the message if "OK" was not returned and/or when i get an error from the modem. it must only look at the "OK: when "AT+CGDCONT=1,"IP","internet","0.0.0.0",0,0" was send.

I hope that makes sense :slight_smile:

2

What do you see from the modem for other commands?

SplitSecComp 3

image

SplitSecComp 4

image

SplitSecComp 5

image

6

The above is a couple of examples.

Sometimes when there is no reception or something is wrong it will return an error......or nothing....then i must have a way to resend the at command.

7

When you send the AT+CGDCONT you could start a Trigger node set to Send Nothing then after a delay (set to the timeout which you expect to receive OK in) to loop back to resend the command. On the output of the serial node use a Switch node to detect OK and use that to send msg.reset to the Trigger node to cancel the timeout.