GE Industrial Solutions Entellisys Integrator’s Guide - Manual (Page 18)

Integrator’s Guide 18
1.2 Interfacing to the Alarm Handler
The set of registers beginning at 0648h provides the means to interface to each CPU’s Alarm
Handler functionality. Each pair of 32-bit values represent the current state (read only) and the
acknowledge setting (read/write) for each alarm type. Each value represents the states for all of
the circuit breakers in the system as denoted in Format Code F722, one bit for each. A 1 in the
bit field position for a given circuit breaker in the state register indicates that the alarm
condition is currently active, while a 0 indicates the condition is not currently active.
When a condition passes from inactive to active, the corresponding ACK bit in the next register
will be set to 1. At this point an external program may acknowledge the alarm by writing a 0 to
that bit location. It is important for the external program to first read the ACK register and mask
the new value such that the states represented by the other bits remain intact. The following
state table describes how the HMI interfaces with the CPU to update its indicators.
Figure 1-1 Alarm state transition diagram
System Initialization
Alarm Condition
Occurs
Start
ACK: 0
Status: 0
HMI Color:
Green
ACK: 1
Status: 1
HMI Color:
Blinking
Red
ACK: 0
Status: 1
HMI Color:
Solid
Red
ACK: 1
Status: 0
HMI Color:
Yellow
Condition
Goes Normal
HMI
ACK
Condition
Recurs
Condition
Goes Normal
HMI
ACK
Alarm State Transition Diagram