Redundant D20/D200 Systems - GE D20 Installation And Operation Manual

GE Energy
Connections and Configuration
Redundant To implement a redundant D20/D200 system, you need:
D20/D200 •
A second CCU, built and configured the same as the first CCU
Systems
•
RS-232 Switch Panel(s)
•
Two RS-232 Switch Panel Monitor and Control cables, referred to as Watchdog
cables, connecting each CCU to the RS-232 Switch Panel. Refer to "Procedure:
Installing Watchdog Cables" on page 85 for details.
•
One inter-CCU communications cable, providing either a Ping connection, or a
(D.20) HDLC connection, between CCUs A and B. The method used depends on
the availability of serial and D.20 ports. As appropriate, refer to:
− "Procedure: Installing a Ping Cable" on page 85
− "Procedure: Installing an HDLC Cable" on page 86.
•
Serial communication cables. The number of serial cables depends on your
system configuration. Serial connections from CCUs to your field equipment are
cabled and switched through the RS-232 Switch Panel. The RS-232 Switch
Panel switches up to eight communications links to the Standby CCU, in the
event of a failure of the Active CCU. See "Procedure: Connecting Serial
Communi-cation Cables" on page 86 for details.
Note: Refer to "Required Components" on page 84 for component part numbers
Note: Refer to "
Note: The RS-232 Switch Panel is not equipped with EMI protection
General
Full
, continued
and functions.
D20/D200 Redundancy
D20/D200 redundancy.
circuitry. If the connection length exceeds 3m, a Serial Surge
Protection Panel (GE item number 540-0249) or equivalent protection
device should be installed.
Installation and Operations Guide
" on page 39 for a description of
994-0078-2.00-7
D20/D200
83