GE Industrial Solutions Entellisys System User Manual - Manual (Page 52)

Single point functions 52
5
The operation of the Messenger and Entellisys CPU based on the state of the protection options
is summarized in Table 5-2 below:
Table 5-2 Protection options and operation of Entellisys CPU and Messenger
ST Option
(Messenger
config) IOC Option
(Messenger
config) Switchable
ST/IOC
Option
(Messenger
config) Options at
Entellisys CPU Notes
Enabled Enabled Don’t care NA – CPU will
have ST will set
Messenger IOC CPU: performs ST and sets Messenger’s IOC at
user setting.
Messenger: performs ST at max setting;
Messenger has analog IOC at max, digital IOC at
user setting. CPU cannot change Messenger
protection options.
Enabled Disabled Don’t care NA – CPU has
ST only CPU: performs ST at user setting.;
Messenger: performs ST at max setting. No
analog or digital IOC. CPU cannot change
Messenger protection options.
Disabled Enabled Don’t care NA – CPU sets
Messenger IOC CPU: sets Messenger’s IOC at user setting.
Messenger has analog IOC at max, digital IOC at
user setting. CPU cannot change Messenger
protection options.
Disabled Disabled Disabled Not a valid
state CPU: performs ST at default setting or user
settings if they have been changed.
Messenger: performs ST at max setting, digital
IOC at max setting. No analog IOC. CPU cannot
change Messenger protection options.
Disabled Disabled Enabled CPU not
operating Messenger: performs ST at max setting;
Messenger performs digital IOC at max or
previous user setting. No analog IOC.
ST ON, IOC ON CPU: performs ST and IOC at user setting.
Messenger: performs ST at max setting, digital
IOC at user setting. No analog IOC.
ST ON, IOC OFF CPU: performs ST at user setting.
Messenger: performs ST at max setting. IOC can
only be turned OFF if ST is ON.
ST OFF, IOC ON CPU: sets Messenger’s IOC at user setting.
Messenger: performs digital IOC at user setting.
No analog IOC. ST can only be turned OFF if IOC
is ON.
ST OFF, IOC OFF
Invalid
command
Messenger: does not change protection
functions; current ST and IOC options and
settings continue to run.