Patton electronic 1080A-64 - Manual (Page 23)

23
The “Error” Indicators
The “Error” indicator LED has three functions:
1. When the 1080A Series unit is in test mode (green “Test” LED is lit),
the error LED glows red when bit errors occur.
2. When not in test mode (green “Test” LED is off), the error LED is
used to indicate an RTS streaming condition. (See Section 5.2) for
information on the anti-streaming circuitry.
3. The “Error” LED is also used to detect line quality, such:
— The improper use of flat (non-twisted pair) cable to connect the
modems.
— One or more broken wire in the 4 wire twisted pair cable.
— The use of low quality twisted pair cable to connect the
modems.
— Broken or corroded connector.
Note In detecting line quality the “Error” LED indicator is designed for
4 wire twisted pair cable only, and may not function properly with
two wire cable.
Setting Up The “Error” LED To Test Cable Quality
If there is any question as to the quality of your line we recommend the
following test:
1. Disconnect both local and remote modems from their RS-232 inter-
face. Make sure “TD”, “RD” and “RTS” LEDs are lit red.
2. Set input impedance of both modems to 200¾. (S3-1 “On”, S3-2
“Off”).
3. For Model 1080A , set data rate on both modems for 9.6 kbps .
4. On local modem set “Carrier Constantly On”. (S1-8 “Off”)
5. Set remote modem to RTS control (S1-8, “On”).
6. Place both front panel toggle switches to neutral position. (Test Led
will not light)
7. Connect both modems to the 4 wire twisted pair cable.
Reading The Test