300 BPS DCM-2 Modem (260-1173)     Selftest            Faxback Doc. # 5980

TEST MODE OPERATION
If you have communication problems, first check all your connections and
cables!

If neither you nor the person you're communicating with locate a connection
or cable problem, run the LOCal Test (both computers should run this test).
If both Modems pass the LOCal Test, run the REMote Test together. If both
systems pass the REMote Test, and you're still having problems with data
transfer, contact your nearest Radio Shack Computer Center.

LOCal Test
The LOCal Test checks your modem's filters, power supply and circuitry. If
one of the modems fails the LOCal Test, isolate the problem and solve it. 
The most common cause of failure is a damaged cable or improper connection.

1. Set your Modem's POWER Switch to ON.
2. Set the TEST Switch the LOC (since the Modem II always runs the Test
   first, you can have the Mode Switches set to any combination). The modem's
   CD light will come on.
3. Type some letters and/or numbers on your Computer's keyboard. If what you
   type is displayed on your Screen, your Modem has passed the LOCal Test. 
   If the characters are not displayed, the Modem has failed the test.
4. If your Modem failed the LOCal Test (the typed characters did not appear
   on your screen), check the cables and connections. Then run the test
   again. If both modems pass the LOCal Test and the problem persists, run
   the REMote test.

TO GET OUT OF THE TEST MODE....

How you get out of the Test Mode depends on how you got into it. In the Man-
ual Mode, just set your Modem's POWER Switch to OFF or set the TEST Switch 
to OFF.  If you're in the AUTOmatic Mode and got into the Test Mode by 
typing QX, set FORCE DTR to OFF and then back to ON. Your Modem will then 
execute according to the Mode Switches.

REMote Test

If both of the modems pass the LOCal Test and data transmission is still
inaccurate, run the REMote Test. This test loops the RS-232 data from the
modem receiver to the driver. In doing so, it checks the operation of the
modems, terminals, and phone connections. You'll need the cooperation of
another person who is using a modem.

1. Establish communication with the other person.
2. The other person should set his/her TEST Switch to REM (if they are using
   a Modem II).
3. Set your TEST Switch to OFF.
4. Type some letters and/or numbers on your keyboard. If the characters are
   displayed first on the other Video Display and then on your Display, both
   systems have passed the REMote Test. Repeat the test, reversing the
   switches and having the other person type, just to be sure.

If the characters don't appear on both screens, both you and thee other per-
son should repeat the LOCal Test. If the LOCal Test does not detect any 
problems, but the system still doesn't pass the REMote Test, you've probably 
got phone line problems. If the situation persists, contact your phone 
company.

(css 08/04/93)