User's Manual

Models CH45
EIA 422 or 485
4-2
5. Are the FD/HD Jumpers, the Repeat Jumpers, and NORM / INVERT Jumpers set to the proper position
for the application? (Are all four FD / HD Jumpers set to the same position?)
NOTE
If the Link/Repeater is not connected directly to an IED, determine that the electrical signal
received by the Link/Repeater is not corrupt. The Link/Repeater only repeats the signal it is given,
it does not re-clock or re-generate the signal.
6. Review the IED's software and protocols. Does the IED have physical "Handshaking" requirements
and have the appropriate settings on the IED been made to compensate for these requirements?
7. Consult factory.
NOTE
The diagnostic LEDs only illuminate when there is signal traffic and are not illuminated during signal
"quiet" times. If during quiet time, TE and TO are illuminated, it suggests either a polarity reversal (pin
2 with pin 1) or that the IED is biased pulling the “A” (+) line with respect to the “B” (-) line. After
checking the polarity on the connections, refer to Section 3.5.
The diagnostic LEDs may "flicker" when data is passing. This is normal operation.