User manual

Confidential, the whole present document is the sole property of Maestro Wireless Solution Ltd.
43
11. REMOTE AT COMMAND BY SMS
This feature is to control the modem to interpret AT command from incoming SMS, executing it, and return the result to
sender by SMS.
The user can enable the modem to receive AT command by incoming SMS. See following about AT+SMSAT command
.
11.1. Description of the Operation
5. When enabled, the modem will treat the incoming SMS as a source of AT command only if all of the following
conditions (a,b and c) are fulfilled :
a. The content of SMS sent to the modem is using standard 7-bit GSM data decoding scheme,
b. The first 6 characters of the SMS content matches the <key> parameter set by AT+SMSAT command, (default key
is “000000”)
c. The 7
th
and 8
th
characters of the SMS content is “AT” (in capital letters)
6. If SMSAT is enabled , the modem will read each incoming SMS, if the conditions mentioned in 1 are matched the
message will be executed, even it is an invalid AT command
7. When using SMSAT feature, only +CNMI:x,1,x,x,x setting could be used (i.e. incoming message will be stored in SIM
card).
8. The maximum length of the AT command is limited by length of SMS, i.e. 160-6 = 154 characters
9. When the SMS AT command is executed , all intermediate and final responses will be buffered recorded, then return to
the sender’s phone number in one single SMS.
10. If response(s) of the AT command is(are) more than 160 characters, only the first 160 characters will be returned.
11. In case the modem cannot get terminal response within 26 seconds, the modem will then abort the command, and
return intermediate responses (if present).
8. If the SMSAT feature is enabled, all incoming SMS, either with valid AT command or not, will be erased. This is to
prevent SIM card memory from fully filled, such the modem will not receive new SMS.
+CSQ: 17,0 OK
Step 1 : send AT command to
modem by SMS
000000AT+CSQ
Step 2 : modem execute and
return response by SMS