Plc Program Example - HEIDENHAIN TNC 426 PB/M Technical Manual

Table of Contents

7.6 PLC Program Example

Special cases

The following PLC program example was written on a PC with the PLC

programming software PLCdesign. PLCdesign is supplied together with

additional comprehensive PLC program examples in data form.

The PLC program is divided into various PLC modules, where each module

performs a specific task. This will help you to quickly recognize the program

structure and easily insert your own functions.

A file known as the documentation file describes the PLC programming

example, which can be output by PLCdesign in addition to the individual PLC

programs (see the User's Manual for the PLCdesign PLC programming

software). In the right column of the documentation file you will find the

source code of the individual modules. This was created by the programmer

using symbolic operands and label names. The left column shows the

statements lists (STL) as they are needed by the TNC. The compiler

automatically generates these statement lists.

This juxtaposition of source code and statements list is very helpful for

understanding the program. Abbreviations were defined for the symbolic label

numbers and symbolic operands contained in the source code. These

abbreviations clearly identify the functions and thereby make the program

more understandable.

The following is an example for the definition of a general symbol name, in

which individual concepts are separated by an underline "_":

MG_active_PWM_axis

Interface operands PLC-NC or NC-PLC, inputs and outputs, timers and

counters, and positive and negative edge markers are always globally effective

and are therefore not indicated as such.

NP_M2008_X_InPos

I_release_tool

TS_5_clamp_unclmp

CS_RS_Err_ReStart

Description of operand function by any text

Status: Enter if the operand type is not

Input: L = locally effective (only in the module)

G = globally effective (in all modules)

Input for operand type: M, B, W, D, K

HEIDENHAIN Technical Manual TNC 426, TNC 430