Specifications

C-5

C Buep 19e-Expander driver

Notes concerning the connection of the PCS to a PLC:

• Connect the cable screening to the central common of the control

cabinet.

• Ensure appropriate chassis groundings with regard to the PCS

housing on the one hand and the PLC bus board on the other.

Remember that a copper grounding strip, due to its large surface,

ensures a considerably higher RF conductivity than normal stranded

interconnecting wire.

• Avoid, as far as possible, high frequency interferences, because dam-

ping is very difficult in this case. The PLC and the PCS are electrically

isolated by optocouplers, but this isolation is not effective in case of

high-speed transients, because optocouplers feature a coupling capa-

citance (although it is very low).

• Ensure clear supply voltage reference points. To facilitate this, the

power supply is potential-free.

• If the supply voltage is influenced by high interferences, use a sepa-

rate power supply for the PCS (24 V, 10 VA). It should be equipped

with appropriate noise filters. In this case, 0 Volt can directly be

connected to protective earth at the PCS.

• Ensure a minimum distance of 200 mm between noise sources and

the PCS/the communication cable. This especially concerns inductors

and frequency converters.

• Please take care that the serial data lines are covered completely (if

possible) by the shield. Use a metallized connector hood at PCS as

well as at the PLC side and ensure a highly conductive connection

between the connector hood and the shield. Please notice that groun-

ding on both sides may require an equipotential bonding conductor

with a cross section of 10 times that of the shield. This is especially

important, if the PCS and the PLC are not connected to the same

common point (if they are for example installed in different control

cabinets). This is necessary to prevent equalizing currents on the

cable shield.