Rockwell Automation Publication 1715-RM001A-EN-P - June 2019
9
The ControlLogix/1715 SIL 2 System
Chapter 1
Diagnostics
See the following table when programming the controller to obtain the status of
the redundancy system.
Add a GSV instruction in the standard task (non-safety task) and use the output
to determine what you want to do if it returns with any code other than 16#2.
Always monitor the status of the redundancy system. If the system is running
properly, the secondary controller is always present and synchronized.
If the system is running normally, the 1756-RM modules show the following
status codes.
Figure 1 - Primary Controller
IMPORTANT
If there is a redundancy switch over, it is always recommended to investigate
why it switched over.
IMPORTANT
When programming your redundant system, program so your redundancy
system status is continuously monitored and displayed on your HMI device.
If your redundancy system becomes disqualified or a switchover occurs, the
change in status is not automatically annunciated. You must program the
system to communicate the change of status via your HMI or other status-
monitoring device
For this information
Get This Attribute
Data
Type
GSV/SSV
Description
Redundancy Status of
the Controller
ModuleRedundancy
State
INT
GSV
IF
Then
16#2
Primary with synchronized
secondary
16#3
Primary with disqualified
secondary
16#4
Primary with no secondary
16#6
Primary with synchronizing
secondary
16#F
Primary looking for update
16#10
Primary locked for update
