MPCI-L210 returns ERROR for command 'AT'

0 votes

Hello,

I am using a chat-script which will send an 'empty' AT command if no SIM pin or mode is provided.  By empty I mean only 'AT' is sent with nothing else following.  I expect to always get an 'OK' response.  However I have experienced situations where 'ERROR' is returned.  Trying to understand why error is returned and how to prevent this.  

My chat-script:

ABORT 'BUSY'
ABORT 'NO CARRIER'
ABORT 'VOICE'
ABORT 'NO DIALTONE'
ABORT 'NO DIAL TONE'
ABORT 'NO ANSWER'
ABORT 'DELAYED'
REPORT CONNECT
TIMEOUT 6
'' 'ATQ0'
'OK-AT-OK' 'ATZ'
TIMEOUT 3
'OK' @/etc/ppp/chatscripts/pin
'OK\d-AT-OK' 'ATI'
'OK' 'ATZ'
'OK' 'ATQ0 V1 E1 S0=0'
'OK' @/etc/ppp/chatscripts/mode
'OK-AT-OK' @/etc/ppp/chatscripts/apn
'OK' 'ATDT*99***1#'
TIMEOUT 30
CONNECT ''

Log of the chat script returning error to 'AT' command:

abort on (BUSY)
abort on (NO CARRIER)
abort on (VOICE)
abort on (NO DIALTONE)
abort on (NO DIAL TONE)
abort on (NO ANSWER)
abort on (DELAYED)
report (CONNECT)
timeout set to 6 seconds
send (ATQ0^M)
expect (OK)
ATQ0^M^M
OK
 -- got it
send (ATZ^M)
timeout set to 3 seconds
expect (OK)
^M
ATZ^M^M
OK
 -- got it
send (AT^J^M)
expect (OKd)
^M
AT
^M^M
ERROR^M
alarm
send (AT^M)
expect (OK)
AT^M^M
OK
 -- got it
send (ATI^M)
expect (OK)
^M
ATI^M^M
MPCI-L210-02S-01^M
^M
OK
 -- got it
send (ATZ^M)
expect (OK)
^M
ATZ^M^M
OK
 -- got it
send (ATQ0 V1 E1 S0=0^M)
expect (OK)
^M
ATQ0 V1 E1 S0=0^M^M
OK
 -- got it
send (AT^J^M)
expect (OK)
^M
AT
^M^M
ERROR^M
alarm
send (AT^M)
expect (OK)
AT^M^M
OK
 -- got it
send (AT+CGDCONT=1,"IP","amsc1.com.attz"^M)
expect (OK)
^M
AT+CGDCONT=1,"IP","amsc1.com.attz"^M^M
OK
 -- got it
send (ATDT*99***1#^M)
timeout set to 30 seconds
expect (CONNECT)
^M
ATDT*99***1#^M^M
CONNECT
 -- got it

 

by hartmda asked Oct 10
14 views
0 votes
The ctrlM that precedes each command is not needed. The failing  pattern appears to be that the pattern CtrlM A T Ctrl M is rejected but sending A T CtrlM with no preceding CtrlM is fine.
I think the protocol guidelines are:
- no preceding CtrlM
- ender is typically CtrlM CtrlJ (<CR><LF>)
by grampy answered Oct 10
by grampy edited Oct 10
website banner