User's Manual

Model CH45

EIA 422 or 485

1-8

that the illumination of the LEDs corresponds with activity in the unit. See Figure 7 for LED

patterns and signal paths.

2413

REP

OFF

2413

REP

OFF

243

REP

OFF

Repeat Mode SelectedNormal Transmission Normal Receive

FIGURE 7. Diagnostic LED patterns and signal paths

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.

1.2.9 Power Connections

Model CH45 is powered through a blade connector when inserted in the DYMEC-DynaStar

3900 15 slot Chassis: Model CH45 has an internal DC/DC converter that isolates the system

and earth ground from signal ground on the DB9 Connector. Care must be taken when cabling

not to short these together as the SWC capabilities will be compromised.

1.2.10 Peripheral Equipment

1.2.10.1 IED

An IED is any intelligent electrical device such as: a computer, RTU, PLC, "smart"

meter, relay, etc., that has the ability to communicate data via EIA 422 or EIA 485

format. The IED should have a communication port for the connection of the

Link/Repeater. If the IED's communication port connector does not accept the

Link/Repeater to be plugged in directly, an adapter must be made to accommodate the

connection. Care should be taken to assure that the correct signals are connected to

each other. See Figure 2 for the Link/Repeater's pin signal assignments. Check your

IED's equipment manual for its signal assignments.

The IED must also have intelligent software to execute the data communication. This

intelligence needs to logically manage the data and signal traffic, including any

addressing, token passing, "handshaking", data formatting and scheduling.

1.2.10.2 Fiber Optic Cable (FOC)

The selection of the fiber optic cable is important. High quality cable can assure the

maximum performance of your Link/Repeater. Important factors to consider are the