HL7748 Connecting to a Network


I am trying to get an HL 7748 to send SMS and eventually data. I have it on a mangOH red board, and am using the Sierra Wireless sim that was provided with the board. (The board was originally sent with a WP8548, and I have no problem sending SMS messages with that chip). When I switch out for the HL 7748, the SMS messages do not work. When I send an at+cops?, I get +cops:0 as a reply. Other replies include +cereg :0,3 +csq:99,99 +creg:2,3 +cpin :ready . With the WP, I got +cops:0,0,“AT&T Sierra Wireless”,2 +csq:26,0 +cereg:0,4 . So first of all, it seems the HL is not registered or connected to the network. It is an LTE capable chip, as the WP8548 is only 3G I believe, so that may have something to do with one working and the other not.

As someone who is new to cellular development, is there ANY documentation for the Sierra Wireless chips in terms of how to manually set registration/configurations/data service, etc? I have the AT command reference r4, but I wish there was an application note that explained how to achieve certain tasks with the AT commands. I will need to be able to send SMS messages with it, and also use a cellular data connection to connect to a server on the web. Any help, or links to more info will be much appreciated!!



Based on below, the HL7748 hasn’t registered (attach) to network.
+cereg :0,3 +csq:99,99 +creg:2,3

HL7748 is a LTE/CAT-M1 product, please ensure network’s APN is properly set with AT+CGDCONT command before preforming network attach i.e. AT+CGATT. You can get module’s attachment status from AT+CREG or AT+CEREG. Once it has attached to network, then you should be able to send SMS.


Ok thank you. I need to look at that again. But I did find out that I cannot send an SMS to a non NEO sim device. I am able to go to the Neo SIM card webpage and send an SMS to my device , so I can RECEIVE SMS messages successfully that way.