GE Industrial Solutions Entellisys System User Manual - Manual (Page 129)

Discrete inputs/outputs 129
10
10.1.1.2 Redundant discrete I/O
Redundant discrete I/O configurations require both CPUs to have same number of discrete I/O
boards. Discrete I/O boards connect to terminal boards using a 68-pin SCSI cable. Connections
from output terminals are wired to the “OR” board and then to the output relays. Input terminal
connections are wired directly from relay blocks. Presence of the “OR” board and same number
of discrete I/O boards in both CPUs are indicators of redundant configuration.
Figure 10-2 Discrete I/O in redundant configuration
10.1.1.3 Discrete I/O boards
Discrete I/O boards supported by and certified for the Entellisys systems are PMC464 from
Acromag Inc. This board supports 64 discrete I/O points with TTL logic (+5 V).
CAUTION: Applying higher voltage may damage the board.
For support of 128 points, two such boards are required. Points on the board can be configured
as inputs or outputs. By default on power up all points are configured as inputs, however during
the booting process CPUs reconfigure boards according to the configuration specified by the
HMI. Discrete I/O points from 1 through 48 can be configured as inputs or outputs in clusters of
eight. The first eight I/O points can be configured as either inputs or outputs. The next eight I/O
points can be configured as inputs or outputs, etc. Set the direction of discrete I/O points from
49 through 64 on a one-by-one basis; the eight-point cluster rule does not apply to them. Each
input can be set independently to one of five debounce settings: one value disables debouncing
or sets it to 0, and the other four set the debouncing to 1.4us, 10.4us, 408.8us, and 3.276ms. All
configurable parameters of the boards mentioned here are set through the HMI. For more
detailed information on the board's specifications please refer to the board’s user manual.
V+ V-
PMC464
INPUT
RELAY
BLOCK
OUTPUT
Board
"OR"
POWER SUPPLY
TERMINAL BLOCK
COMMON FROM ASSOCIATED
PMC464 CARD
GND from "OR"
SIGNAL LINES
TO DEVICES
PMC464
ASSOCIATED PMC464
COMMON FROM
CARD
COMMON FROM
ASSOCIATED PMC464
CARD
INPUT
RELAY
BLOCK
RELAY
BLOCK