I am attempting to send SMS messages through CNS commands on a MC5728V. The code I’ve written can receive and process incoming messages, but when I try to send a message, the message will be sent to it’s destination completely blank. The modem doesn’t report any errors when I write the message, and reports that there was no error when it is sent.
Here is the log of the communication between the host and the modem:
#send SMS header
Sending : 7E 00 C6 2B 00 20 03 03 00 F0 05 BA 11 00 BC 10
11 00 01 00 B6 00 00 06 40 00 01 00 00 00 02 00
00 00 00 0A --NUMBER TO SEND SMS TO-- 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 02 13 06 28 15 27 55 00 00 00 00
00 00 00 00 00 00 00 00 00 00 01 7E
#modem acknowledges
Receiving: 7E 00 0A 6B 00 20 03 04 00 F0 05 BA 11 00 00 7E
#Send (only) data packet
Sending : 7E 00 1C 2B 00 20 03 03 00 F0 05 BA 11 00 12 10
11 01 03 00 0C 48 65 6C 6C 6F 20 57 6F 72 6C 64
21 7E
#modem acknowledges
Receiving: 7E 00 0A 6B 00 20 03 04 00 F0 05 BA 11 00 00 7E
#Register to receive the sent message notification
Sending : 7E 00 0A 2B 00 20 05 05 00 F0 05 BA 11 00 00 7E
#modem acknowledges
Receiving: 7E 00 0A 6B 00 20 05 06 00 F0 05 BA 11 00 00 7E
#Send outbox to network
Sending : 7E 00 0A 2B 00 20 04 03 00 F0 05 BA 11 00 00 7E
#modem acknowledges
Receiving: 7E 00 0A 6B 00 20 04 04 00 F0 05 BA 11 00 00 7E
#notification
Receiving: 7E 00 10 6B 00 20 05 07 00 00 00 00 00 00 06 10
11 00 00 00 00 7E
As far as I can tell, based on the CnS reference document, this should result in an SMS containing “Hello World!” should be sent to the phone number in the header. An SMS is sent to that phone number, but it contains no text, it is completely blank. To make sure the modem was working properly, I sent an SMS via AT command, and it arrived in good order, so I’m pretty sure this isn’t a hardware or configuration problem. Has anyone else had similar problems? If so what were your solutions?