COURIER HIGH SPEED MODEMS
TEST PATTERN⎯S16=4
The test pattern can be used instead of your typed data during Analog Loopback (AL) or Remote Digital Loopback (RDL), using &T commands or S16. The test pattern is available at all speeds. At 300 bps, the modem's serial port rate must be fixed (&B1) and the link rate fixed at 300 bps (&N1). At rates over 9600 bps, just set the modem for a fixed serial port rate (&B1).
To use the test pattern during AL testing with S16, type the following command. The test pattern is sent through the loopback.
AT&M0S16=5D
To use the test pattern during RDL testing with S16, type the following command:
AT&M0S16=12
To use the test pattern with the &T AL or RDL tests, insert the test pattern command, S16=4, before issuing the test command. The first of the following commands initiates AL, the second RDL:
ATS16=4&T1
ATS16=4&T6
The test pattern alone (ATS16=4) is used for testing equipment and the phone line. When S16 is set to 4, the modem transmits the test pattern upon connection with a remote modem.
Ending Testing with the Test Pattern
Pressing any character key cancels all test pattern tests and hangs up the modem. If you used Register S16, be sure to reset Register S16 to Data mode when you reset the modem to its error control defaults, for example, ATZ or AT&M4S16=0.
REMOTE DIGITAL LOOPBACK⎯S16=8
Responding Modem
The responding modem must be ready to act on the Courier's RDL request. U.S. Robotics high speed modems should be set to &T4. If they do not have &T testing capability, they should be set to S16=8.
