7
3 Modules of the PLC Program
3.1 System Modules
:001 20ms clock module
Called at every 20 ms
Mandatory activities:
$"
Handling of alarm signals
$"
Handling of limit-stop positions
$"
Manipulation of ref-point switches
$"
Handling of other signals demanding fast serving
$"
Issuing command J1 at the end of the module.
Prohibited instructions:
Instruction W and any organization of program preventing the module from being completed
in its own time segment ARE STRICTLY FORBIDDEN!
:000 Cyclic PLC module
Called:
$"
at the beginning of "life cycle"
$"
in the next PLC time segment (if command J0 is issued)
$"
under the effect of instruction G000.
Mandatory activities: initialization of the system
Prohibited instructions: none
Recommended program organization in module :000:
:000
C004 ;init module
:100
*
*
*
PLC program
*
*
*
NY405 ;no emergency state
G100 ;cycling
E
G000 ;init in emergency state
Z
J0
3.2 Modules of Optional Uses
:002 - :199 except for:
:005 - :019 NC subroutines
:050 - :059 subroutines provided by the manufacturer.
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