AirPrime with HL7588 usb port disconnecting

Hello. I’m running an AirPrime board with an HL7588 module and running AT commands on a terminal and via a script. I’m seeing issues with usb port disconnecting (I think it may be resetting but can’t be sure). The led’s on I/O bank go solid & UE goes to RRC state IDLE. Seems to occur around network registration, or sending UDP packet. I can’t find anything in PTS or release notes to explain this. regards

Also, when I reconnect in a terminal I see the following, suggesting the HL7588 module is resetting
+SIM: 1
+KSUP: 0

Hi @cdefant,
Maybe you can provide the steps/AT command you inserted and the script you run. It will help understand the situation

Thanks for the reply Vianney, I’m using a cabled setup & call box with only primary antennae selected,
+COPS: (1,"","",“00101”,7,0),(3,“Verizon”,“Verizon”,“311480”,7,)

All responses are OK, Call box MNC is 1F. disconnection/power cycling seems to occur after at+cops command

Hello again Vainney, From PXT side, connection seems fo be failing at RRC authentication request, but because the usb keeps going down, I can’t see the associated error codes

to clarify no response from UE to RRC[AuthenticationReq].
If I disable security on network side, HL7588 sends Authenticationresp [failed] (i.e. HL7588 is expecting authentication from network side)

Hi @cdefant,
Sorry for late response. Can you provide more info to understand this case

  • Which firmware are you using? We highly recommend customer using the latest which is posted in Sierra official
  • From the previous comment, you meant that security is disabled from the network but the module still sends Authenticationresp, doesn’t it? In theory, the module sends a response only when the network sends a request. I am not sure why it is working like that on your site. Can you please share output flows of the module when trying to attach the network.


Hello, using latest firmware RHL75xx.V.3.15.151600.201802071640.x7160_1
HL7588, & latest USB driver from Sierra. We have resolved the problem by putting the kit in an RF shielded box.

Sorry should specify resolved the majority of the problem. I can still see ocasional port crash, when checking state of PS attach. I have not been able to reproduce this issue on command line, just see it in the script. I get the following error code:
b’AT+CGATT?\r\r\n+CME ERROR: SIM not inserted\r\n’
Timeout or error on command AT+CGATT.
SIM card is in its slot (inside RF shield box). could crash/board reboot trigger this error code?

Hi @cdefant,
You cannot reproduce the issue on AT command line, it means there is no issue on HL7588. It might be from the script. Can you share it then we can check where is the issue from?

Here is the Python script we use to run AT commands. (2.3 KB)