Rockwell Automation T3464 ICS Regent AC Guarded Digital Output Module - Manual (Page 8)

AC Guarded Digital Output Module (T3464)
8
Industrial Control Services
Diagnostic Message Display
This four-digit display provides additional fault diagnostics
(such as blown fuse, AC power problems, wiring faults, etc.). If
one or more fault conditions are present, the fault messages
are displayed in rotation for approximately one second each.
These fault messages are self-clearing (which means, for
example, that replacing a blown fuse will clear the blown fuse
message). However, the module’s FAULT indicator can only
be cleared by a voted reset.
Indicator messages are described in the section Maintenance,
beginning on page 18.
Shutdown Indication
Upon loss of communications with the controller, output
modules enter either a shutdown or hold fault mode. If the I/O
unit is set to shutdown, the diagnostic message display will
show Shud when communications with the controller are lost.
If the I/O unit is set to hold, diagnostic message display will
not display this message (see page 14, Fault Mode Jumper).
When the module is installed in the I/O chassis or when logic
power (from the I/O power supply modules) is first applied to
the module, it will be in the shutdown mode until the first
output scan, regardless of the fault mode jumper settings.
Also, removing two I/O transceiver modules, two I/O power
supply modules, or two power legs will cause the module to be
in the shutdown mode.
Application
Each module has separate power terminals for switch groups
1-8 and groups 9-16. The two groups are electrically isolated
from each other by a minimum of 2500 volts. If the phase
difference between separate power sources cannot be
guaranteed to be less than one degree, both groups should be
wired to the same AC circuit. The microcomputers monitor
this phase difference to validate timing data derived from the
AC power.
When a crowbar circuit blows a fuse, approximately 16
additional amps of current flows through both the line and
neutral circuits until the fuse opens. Normally, only a small
Note: