User guide

Software

890 USE 108 00 August 2001

Sequential

Function

Charting

SFC is especially suitable for sequential processes because it allows you to

generate programs that are organized in steps (rather than in linear ladder logic

sequence). A sequential function chart can solve multiple networks in a parallel link

or one in a choice of several networks in a selective link. Logic is solved within a

block until a specified transition event informs the CPU to move to the next step.

SFC allows application software to be created in a format that more closely emulates

an actual machining procedure or process flow. It can help improve system

throughput by solving only those networks specified by transition events rather than

moving linearly through each network in the program on every scan.

Modsoft macros simplify the task of generating and updating large numbers of

repetitive network structures. They allow you to create a repetitive structure once

only, then specify the node values using macro parameters rather than standard 984

reference numbers. Each macro can contain up to 66 macro parameters by using

(*) wild card characters in your naming scheme, you can create thousands of

parameters per macro.

For a detailed description of full-feature Modsoft and its operations, see the Modsoft

Programmer User Manual (890 USE 115 00).

Note: If you are using full-feature Modsoft to develop application logic for a

Compact system that will use full Modsoft as its permanent programming software,

be careful about the use of SFC and macro ladder logic.

You can develop your programs using the /p switch. This switch prevents you from

creating SFC logic and does not reserve any registers or coils for SFC us. Do not

use macros in this case.

Alternatively, you may develop programs with SFC and macros, then use the

convert-to-file menu in Modsoft to produce an equivalent program in standard

ladder logic that will run with other panel software.