COBHAM Satcom EXPLORER 540 User & Integrator's Manual page 170

ATCO response codes
The following response codes apply to the AT commands supported by SMS.
Code Text
General codes
0 Complete
1 Unexpected software error
2 Local file open error
3 Directory not found
4 File not found
5 Error renaming file
Context Management codes
13 Context activation error
FTP Management codes
20 FTP hookup fail
21 FTP login fail
23 FTP 'cwd' fail
24 FTP data connection fail
26 FTP xfer command fail
29 FTP socket fail
31 FTP xfer timed out
_IGETFW command codes
40 File in use, cannot download
98-148232-K
Explanation
Operation completed successfully.
Software error.
_IGETFILE: could not open local file after download.
_ISENDFILE: could not open local file.
_IUPDCFG: Loading configuration failed. Incompatible file
format.
Could not find specified directory on local file system.
Could not find specified file name on local file system.
Could not restore after failed upgrade.
Context activation failed. Could be problem with PS attach,
SIM subscription, APN, network or connectivity.
Connection to FTP server failed. Problem could be server
unreachable or specified IP address or server name invalid,
or connectivity failure.
FTP user name or password incorrect.
Could not change to working directory on FTP server.
Could not establish an FTP data connection with the
server.
Could not initiate data transfer on an established
connection. May be caused if filename not found.
Error while reading or writing FTP data socket.
FTP client timed out waiting for socket ready (read or
write), e.g. due to loss of connectivity during transfer.
The file to be downloaded is the same as the image
currently in use.
Appendix B: Command reference
AT commands
B-12