Schneider Electric SR2MAN01 Discrete Inputs, Description, Use as a Contact, Normally open mode

LD Language Elements

Discrete Inputs

Description	The Discrete Inputs can be used exclusively as contacts in the program.
	These contacts represent the status of the input for the smart relay connected to a
	sensor (push button, switch, sensor, etc.).
	The contact number corresponds to the number of terminals of the associated input:
	1 to 9, then A to R (except for letters I, M and O) according to the smart relay and
	the possible extension.
Use as a Contact
	This contact may use the direct state of the input (normally open mode) or its inverse
	state (mode normally closed), see below.
	Normally open mode:
	Symbol of a normally open contact:
		I -
	A normally open contact corresponds to the use of the direct state of the input. If the
	input is supplied, the contact is said to be conducting.
	Example: Using a pushbutton to switch a lamp on and off.
		I1	Q1

If input 1 is supplied, contact I1 is closed, and coil Q1 is activated.

Normally closed mode:

Symbol of a normally closed contact:

i -

A normally closed contact corresponds to the use of the reverse state (logical complement of the direct state) of the input. If the input is supplied, the contact is said to be non-conducting.

Example: Controlling a lamp using an input in reverse state.

i1 [Q1

If input 1 is supplied, contact i1 is open, and coil Q1 is non-activated.

SR2MAN01 11/2007 89