Programming, 1 program structure, Introduction 2. programming – Lenze PM94P01C User Manual
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PM94P01C
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Introduction
2.
Programming
2.1
Program Structure
One of the most important aspects of programming is developing the program’s structure. Before writing a program, first
develop a plan for that program. What tasks must be performed? And in what order? What things can be done to make
the program easy to understand and allow it to be maintained by others? Are there any repetitive procedures?
Most programs are not a simple linear list of instructions where every instruction is executed in exactly the same order
each time the program runs. Programs need to do different things in response to external events and operator input.
SML contains program control structure instructions and scanned event functions that may be used to control the flow
of execution in an application program. Control structure instructions are the instructions that cause the program to
change the path of execution. Scanned events are instructions that execute at the same time as the main body of the
application program.
Header - Enter in program description and title information
;********************************* HEADER *********************************
;Title:
Pick and Place example program
;Author:
Lenze - AC Technology
;Description:
This is a sample program showing a simple sequence that
;
picks up a part, moves to a set position and places the part
I/O List - Define what I/O will be used
;********************************* I/O List ******************************
;
Input A1
-
not used
;
Input A2
-
not used
;
Input A3
-
Enable Input
;
Input A4
-
not used
;
Input B1
-
not used
;
Input B2
-
not used
;
Input B3
-
not used
;
Input B4
-
not used
;
Input C1
-
not used
;
Input C2
-
not used
;
Input C3
-
not used
;
Input C4
-
not used
;
;
Output 1
-
Pick Arm
;
Output 2
-
Gripper
;
Output 3
-
not used
;
Output 4
-
not used
Initialize and Set Variables - Define and assign variable values
;**************************** Initialize and Set Variables *****************
UNITS = 1
ACCEL = 75
DECEL =75
MAXV = 10
;V1 =
;V2 =
DEFINE Output_on 1
DEFINE Output_off 0