SMS error - CMS Error 304 - bad PDU

[Pat Sewall]

Hello:

 

I'm attempting to send a SMS message to a generic GSM modem module and I'm getting a CMS Error 304 most of the time; sometime it works. Does anybody have a clue why this might happen as it appear the PDU encoding was correct.

 

Message sent: 0x51 / 0x0009
41 54 2b 43 53 43 53 3f 0d                      | AT+CSCS?
write: [AT+CSCS?<cr>]
read : [AT+CSCS?<cr><cr><lf>+CSCS: "GSM"<cr><lf>OK<cr><lf>]
Message received: 0x51 / 0x001d
02 41 54 2b 43 53 43 53 3f 0d 0d 0a 2b 43 53 43 |  AT+CSCS?   +CSC
53 3a 20 22 47 53 4d 22 0d 0a 4f 4b 0d          | S: "GSM"  OK
Received message type 51
Initialisation completed
Message sent: 0x22 / 0x0009
41 54 2b 43 53 43 41 3f 0d                      | AT+CSCA?
write: [AT+CSCA?<cr>]
read : [AT+CSCA?<cr><cr><lf>+CSCA: "+12063130004",145<cr><lf><cr><lf>OK<cr><lf>]Message received: 0x22 / 0x002c
02 41 54 2b 43 53 43 41 3f 0d 0d 0a 2b 43 53 43 |  AT+CSCA?   +CSC
41 3a 20 22 2b 31 32 30 36 33 31 33 30 30 30 34 | A: "+12063130004
22 2c 31 34 35 0d 0a 0d 0a 4f 4b 0d             | ",145    OK
Received message type 22
Please enter SMS text. End your input with <cr><control-D>:123
Message sent: 0x53 / 0x000a
41 54 2b 43 4d 47 46 3d 30 0d                   | AT+CMGF=0
write: [AT+CMGF=0<cr>]
read : [AT+CMGF=0<cr><cr><lf>OK<cr><lf>]
Message received: 0x53 / 0x0010
02 41 54 2b 43 4d 47 46 3d 30 0d 0d 0a 4f 4b 0d
Received message type 53
AT mode set
Sending initial sequence
Message sent: 0x54 / 0x000b
41 54 2b 43 4d 47 53 3d 32 32 0d                | AT+CMGS=22
write: [AT+CMGS=22<cr>]
read : [AT+CMGS=22<cr><cr><lf>> ]
Message received: 0x54 / 0x000f
01 41 54 2b 43 4d 47 53 3d 32 32 0d 0d 0a 3e    |  AT+CMGS=22   >
Received message type 54
Got response 0
Sending frame: 07912160130300F411000781823312F90000AA0331D90C
Message sent: 0x20 / 0x002f
30 37 39 31 32 31 36 30 31 33 30 33 30 30 46 34 | 07912160130300F4
31 31 30 30 30 37 38 31 38 32 33 33 31 32 46 39 | 11000781823312F9
30 30 30 30 41 41 30 33 33 31 44 39 30 43 1a    | 0000AA0331D90C
write: [07912160130300F411000781823312F90000AA0331D90C^Z]
SM_Block Retry - 0
SM_Block Retry - 1
read : [07912160130300F411000781823312F90000AA0331D90C<cr><cr><lf>+CMS ERROR: 304<cr><lf><cr><lf>OK<cr><lf>]
Message received: 0x20 / 0x0048
02 30 37 39 31 32 31 36 30 31 33 30 33 30 30 46 |  07912160130300F
34 31 31 30 30 30 37 38 31 38 32 33 33 31 32 46 | 411000781823312F
39 30 30 30 30 41 41 30 33 33 31 44 39 30 43 0d | 90000AA0331D90C
0d 0a 2b 43 4d 53 20 45 52 52 4f 52 3a 20 33 30 |   +CMS ERROR: 30
34 0d 0a 0d 0a 4f 4b 0d                         | 4    OK
Received message type 20