Rockwell Automation 57C419 5V-24V DC Input Module - Manual (Page 19)

4Ć3
If you are using AutoMax Version 3.0 or later, see the AutoMax
Programming Executive (JĆ3750) for information about configuring
variables.
4.3 Reading And Writing Data In Application
Tasks
In order for an input module to be referenced by application
software, it is necessary to assign symbolic names to the physical
hardware. In AutoMax Version 2.1 and earlier, this is accomplished by
either IODEF or RIODEF statements in the configuration task. In
AutoMax Version 3.0 and later, you assign variable name using the
Programming Executive.
Each application program that references the symbolic names
assigned to the module must declare those names COMMON.
The frequency with which tasks read their inputs and write their
outputs depends on the language being used. Ladder logic and
Control Block tasks read inputs once at the beginning of each scan
and write outputs once at the end of scan. BASIC statements in
BASIC tasks or Control Block tasks read an input and write an output
for each reference throughout the scan.
4.3.1 Ladder Logic Task Example
run
STARTPB
1050
run LIGHT
The symbolic names LIGHT and STARTPB reference the input
modules that were defined in the rack configuration. The trailing at
symbol @" is not used in Ladder Logic tasks. The symbolic name
run" is local to the Ladder Logic task and does not have I/O
associated with it.
4.3.2 BASIC Task Example
1000 COMMONLIGHT@ \!Fault Light
1010 COMMONSTARTPB@ \!Start PushĆbutton
2000 LOCAL RUN@ \!Line run
3000 !
4000 !
5000 RUN@ = NOT LIGHT@ AND &
( STARTPB@ OR RUN@)
5500 !
6000 END
The symbolic names LIGHT@ and STARTPB@ reference the input
modules that were defined in the rack configuration. The symbolic
name RUN@ is local to the BASIC task and does not have I/O
associated with it.