Modem Return Codes - IBM Aptiva Handbook

Modem return codes

Table 17 lists some codes that the modem sends to your computer in response to the commands you type. They are
called return codes. Not all of the return codes are listed here.
Table 17: Return codes
Digit code Word code
0 OK
1 CONNECT
2 RING
3 NO CARRIER
4 ERROR
5 CONNECT 1200 ec *
6 NO DIAL TONE
7 BUSY
8 NO ANSWER
10 CONNECT 2400 ec *
* When the extended return codes configuration option is enabled, ec indicates the error control method used. Where a value for ec is included
in the error code, the error control method indicated is as follows:
V42bis V.42 error control and V.42bis data compression
V42 V.42 error control only
MNP 5 MNP class 4 error control and MNP class 5 data compression
MNP 4 MNP class 4 error control only
NoEC No error control protocol
172 Appendix C: Modem information
Meaning
Command was carried out without error
Modem connected to the line
Ringing signal detected
Carrier is lost or not heard
Error in the command line
Invalid command
Command line exceeds buffer
Invalid character format
Connected at 1200 bits per second (bps)
No dial tone during the time-out period
The line being called is busy
The line being called did not answer within the time-out period
Connected at 2400 bps