Chapter 4. System Operation
40
PACSystems RX3i Genius Communications Gateway
GFK-2892F
Alarms
Whenever an alarm condition occurs on a Genius Device, a background message (datagram) is transmitted
from the device to the GCG001. This transmission occurs while the alarmed device has the Genius Bus token.
Upon reception, the GCG001 formulates an Alarm message to be passed to the PNC001, which in turn passes
it to the RX3i CPU. The RX3i takes appropriate action and notifies the operator per the logic in the application.
Alarms may be cleared programmatically using either the Clear Circuit Fault COMMREQ (see Figure 30) or the
Clear All Circuit Fault COMMREQ, or via the Genius Hand-Held Monitor (HHM). Note that whenever the HHM is
used to clear a circuit fault, the GCG001 will not be aware of this condition, thus will not have cleared the
corresponding fault. Under these conditions, the
Diagnosis Disappears
Fault will not have been logged and any
subsequent fault from the same point will not be reported to the I/O Fault Table. Be sure to follow up any HHM
clearing of faults with a COMMREQ to clear the same fault(s) in order to eliminate the discrepancy described
here.
Typically, the field problem needs to be investigated and resolved before the alarm can be successfully cleared.
For the alarm to be cleared, the alarm condition must no longer be present and the Genius device must receive
a suitable background message instructing it to clear the alarm notification. If the alarm condition is absent,
the Genius device will cease to exhibit the alarm indication (LEDs will operate normally again). If the alarm
condition is still present, a new alarm cycle will be initiated. See Sections 6.4.5, 6.4.6 and 6.4.4 for related
COMMREQ or
Data_Init_Comm
instructions. Refer to
Genius I/O System and Communications User's Manual,
GEK-90486-1, for further details.
Note: For GCG Firmware prior to V1.1.1
As mentioned in Section 1.10, the behavior of the input references associated with a Genius
Device that has indicated a fault, and which is interfaced to the CPU via the GCG001, is to cause
all inputs to either hold last state or to default to a known state (per GCG001 configuration
parameters). If this behavior is problematic for your application, you can disable fault reporting at
the block, using the Genius Hand-Held Monitor (HHM)
–
see
Report Faults
in the
Genius I/O Analog
and Discrete Blocks User’s
Manual,
GEK-90486-2. The downside is that your application will no
longer be able to automatically sense faults at the corresponding Genius Device. The LEDs on the
Genius Device will continue to indicate Fault conditions; however, no datagram will be issued for
each fault occurrence. An intermediate solution is to periodically query each such device with a
Read Diagnostics
datagram (Section 6.4.4) and parse the response in order to detect faulted
circuits.
