HEIDENHAIN TNC 426 CB, Technical Manual

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December 2001 Submit Programs 7 – 159
7.10 Submit Programs
Submit programs are subroutines that the PLC submits to the NC for
processing. This allows you to solve problems that are very processor-
intensive, require program loops, or must wait for external results. It is a
prerequisite that these programs are not restricted to a definite time frame.
Depending on processor utilization, the TNC provides for a submit program a
certain percentage of its computing power—at least 5%. You start submit
programs from the PLC program. They can access all data memory areas (M/
B/W/D) as the main program can. To prevent problems, ensure that data
processed by the PLC program are clearly separated from data processed by
the submit program. You can place up to eight submit programs in a queue.
Each submit program receives an “identifier” (a number between 1 and 255,
assigned by the NC), which the TNC enters in the word accumulator. With this
identifier and the REPLY function you can then interrogate whether the
program is in the queue, is being processed, or has already been processed.
The TNC processes the submit programs in the sequence in which they were
entered in the queue. If errors occur during execution of the submit program,
the NC sets the following markers:
The TNC lists these markers separately in the submit job. This means that you
can edit the same markers as those in the PLC sequential program without
interfering in its execution. No exact times can be stated for the commands
for managing the submit queue. The processing times given in Chapter 7.7.2
are maximum values.
Set Reset
M4200 Overflow during multiplication NC PLC
M4201 Division by 0 NC PLC
M4202 Incorrectly executed modulo NC PLC
M4203 Error status for PLC module NC NC/PLC
M4204 Reserved for errors that the PLC
programmer would like to catch NC NC