User manual

LD Language Elements

SR2MAN01 11/2007

Introduction

Description In LD programming mode, an application can be created from the interface of the

front panel of the smart relay.

Here is detailed information on all possible elements of a ladder diagram in LD mode

that are recognized and used by smart relays.

To better understand the functions performed by each element, where necessary a

directly usable example is included.

Composition of

Ladder Diagrams

Smart relays accept 120-line diagrams.

z Each line is comprised of a maximum of 5 contacts.

Contacts must be attached to one coil, and the coil is not necessarily on the same line.

Sample Ladder

Diagram

Below is an example of a ladder diagram, as it appears on the display of the front

panel of a smart relay:

Note: When an application requires more than five contacts to activate an action,

the auxiliary relays may be used.

I1 RT1

I3 M3 Z1 SM1

TT1

Menu / OK