GE PACSystems RX7i

Chapter 4. Ladder Diagram (LD) Programming
96 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
4.4.5 Normally Closed and Normally Open Contacts
A normally closed contact (NCCON) acts as a switch that passes power flow if the BOOLV operand
is OFF (false, 0).
A normally open contact (NOCON) acts as a switch that passes power flow if the BOOLV operand
is ON (true, 1).
Operands
Parameter
Description
Allowed Operands
Optional
BOOLV
BOOLV may be a predefined system variable or a user-
defined variable.
NCCON:
If BOOLV is ON, the normally closed contact
does not pass power flow.
If BOOLV is OFF, the contact passes power
flow.
discrete variables in I, Q, M, T, S,
SA, SB, SC, and G memories;
symbolic discrete variables; bit-
in-word references on variables
in any non-discrete memory
(e.g., %L) or on symbolic non-
discrete variables.
No
NOCON:
If BOOLV is ON, the normally open contact
passes power flow.
If BOOLV is OFF, the contact does not pass
power flow.