Siemens v1.0 Manual de Serviço descarregar pdf (Página 97)

Extended example

3.2 Expanding the program

STEP 7 Basic V10.5

Getting Started, 12/2009, A5E02651459-01

3.2.2.2 Querying the position of the bottle and the status of the heating chamber

Introduction

The following steps show you how to program the position of the bottle and the status of the

heating chamber as condition for starting the conveyor.

You query the status of the heating chamber with the help of the "Normally closed contact"

instruction.

Normally closed contact

The following figure shows the icon of the normally closed contact in the program:

---| / |---

The activation of the normally closed contact depends on the signal state of the associated

operand. When the operand has signal state "1," the contact is opened and the current flow

to the right power rail is interrupted. The output of the instruction in this case results in the

signal state "0".

When the operand has signal state "0," the normally closed contact is closed. Power flows

through the normally closed contact into the right power rail and the output of the instruction

is set to signal state "1".

Requirements

● The organization block "Main [OB1]" is open.

● The status of the machine is programmed as first condition for starting the conveyor

(see Querying the status of the machine (Page 95))

Procedure

To program the position of the bottle and the status of the heating chamber as condition for

starting the conveyor, follow these steps:

1. Insert a second normally open contact into Network 2.

2. Interconnect the normally open contact with the tag "LS_1".

1 2 ... 92 93 94 95 96 97 98 99 100 101 102 ... 201 202

Sem comentários

Siemens v1.0 Manual de Serviço Página 97