Alstom MiCOM P846, Technical Manual

Page: 131 / 298

Programmable Logic P846/EN PL/D
MiCOM P846
(PL) 7-7
Rules for Linking Symbols
Links can only be started from the output of a signal, gate, or conditioner, and can only be
ended on an input to any element.
Since signals can only be either an input or an output then the concept is somewhat
different. In order to follow the convention adopted for gates and conditioners, input signals
are connected from the left and output signals to the right. The Editor will automatically
enforce this convention.
A link attempt will be refused where one or more rules would otherwise be broken. A link will
be refused for the following reasons:
•
An attempt to connect to a signal that is already driven. The cause of the refusal may
not be obvious, since the signal symbol may appear elsewhere in the diagram. Use
“Highlight a Path” to find the other signal.
•
An attempt is made to repeat a link between two symbols. The cause of the refusal may
not be obvious, since the existing link may be represented elsewhere in the diagram.
1.6.2 Opto signal properties
Opto Signal
Each opto input can be selected and used for programming in PSL. Activation of the opto
input will drive an associated DDB signal.
For example activating opto input L1 will assert DDB 032 in the PSL
PL
1.6.3 Input signal properties
Input Signal
Relay logic functions provide logic output signals that can be used for programming in PSL.
Depending on the relay functionality, operation of an active relay function will drive an
associated DDB signal in PSL.
For example DDB 360 be asserted in the PSL should the open line detector operate/trip.
1.6.4 Output signal properties
Output Signal
Relay logic functions provide logic input signals that can be used for programming in PSL.
Depending on the relay functionality, activation of the output signal will drive an associated
DDB signal in PSL and cause an associated response to the relay function
For example, if DDB 770 is asserted in the PSL, it will inhibit the voltage supervision
function.