Diagnostic Alarms - GE Mark VIe System Manual

7.4 Diagnostic Alarms

Controllers and I/O packs generate diagnostic alarms to indicate potential issues with control system equipment or the
connections to it (power, networks, and so forth). I/O pack firmware checks raw inputs from hardware and creates alarm bits
at frame rate, queueing any resulting alarms.
• Each type of I/O pack has hardware limit checking based on high and low levels set near the ends of the operating range.
When the limit is exceeded, a logic signal is set. (ATTN_xxxx).
• In TMR systems, a limit alarm called TMR Diff Limt is created if any of the three inputs differ from the voted value by
more than a preset amount. This limit value is configured by the user creating a voting alarm indicating a problem exists
with a specific input.
• If any one of the hardware limits is set, a pack composite diagnostic alarm, L3DIAG_xxxx, where xxxx is created in the
board name. This signal can be used to trigger a process alarm.
• The diagnostic signals can be individually latched, and then reset with the RESET_DIA signal from the HMI.
In addition to inputs, each board has its own diagnostics. The I/O boards have a processor stall timer, which generates the
signal, SYSFAIL. This signal lights the red LED on the front panel and queues and alarm. The watchdog timers are set at 150
ms. If an I/O board times out, the outputs go to a fail-safe condition which is zero (or open contacts) and the input data is put
in the default condition, which is zero.
7.4.1 Controller Diagnostic View
The Controller Diagnostics View in the ToolboxST application displays errors or warnings that occur in the hardware
component and could cause the component to function improperly. Retrieving these messages should be the first step in
diagnosing any hardware or communication issues.
➢ ➢ To open Controller Diagnostics view: from the View menu, select Diagnostics and Controller Diagnostics.
In a duplex or TMR
configuration , use
this drop-down list
to select the
desired
redundancy
component to
retrieve messages
Message
time stamp
Message
fault code
Message
status
(0=inactive;
1=active)
Message
description
Alarm Overview
Click Reset
Click Refresh
Diagnostics to
List to manually
clear messages
retrieve messages
with 0 status
Public Information
Select to display
messages with one
status. Clear to
display all messages
GEH-6721_Vol_I_BP System Guide 169