Specifications

Appendix: FC Bus Auxiliary Devices

Repeaters

Repeaters are optional components on the FC Bus that increase the maximum allowable length and device counts

of the FC Bus. One repeater is counted as one device on the FC Bus. Repeaters are not allowed on the SA Bus.

Table 13 describes how the length and device maximums of the bus change when you add repeaters. The repeater

is specified in Local FC Bus Rules and Specifications.

A maximum of two repeaters can be between any two points on the FC Bus.

Note: Some device models and third-party devices may have reduced capabilities.

Table 13: Repeaters on the FC Bus

With 2 RepeatersWith 1 RepeaterWith No Repeater

Maximums

5,0005,0005,000Maximum Segment Length (ft)

15,00010,0005,000Maximum Total Length (ft)

505050Maximum Device Count Per Segment

10010050Maximum Total Device Count

1 The values in this table represent the recommended 3 conductor, 22 AWG stranded, shielded cable.

2 Some device models and third-party devices may have reduced capabilities.

Configuring Repeaters

The instructions for configuring the repeater for use with the FC bus require that you perform the following:

• Set the baud rate to match the FC bus baud rate.

• Wire the repeater between two segments of the MS/TP bus. If you are using this repeater in a branch, the side

with the branch has double the number of wires terminated. See Figure 17.

•

Set the EOL jumpers on the repeater according to Table 14.

Note: The EOL jumpers are located below the cover of the repeater.

Note: Sides A and B have separate EOL settings. Determine the settings individually.

For repeater installation instructions and important safety information, refer to the repeater manufacturer’s literature.

Risk of Electric Shock: Disconnect or isolate all power supplies before making electrical connections. More than

one disconnect or isolation may be required to completely de-energize equipment. Contact with components carrying

hazardous voltage can cause electric shock and may result in severe personal injury or death.

Table 14: EOL Settings for Repeater

InstructionsJumperSide

At end-of-line: Install both jumpers over Pins 1 and 2 (EOL In).J1 and J2Side A

Not at end-of-line: Install both jumpers over Pins 2 and 3 (EOL Out).

At end-of-line: Install both jumpers over Pins 1 and 2 (EOL In).J3 and J4Side B

Not at end-of-line: Install both jumpers over Pins 2 and 3 (EOL Out).

40MS/TP Communications Bus Technical Bulletin: Appendix: FC Bus Auxiliary Devices