Configuration of synch
This section of the manual is not yet written. It will explain how to
configure the synch. Some of these are settings in the [PLC]
section, others are common to all modules, but they're all collected here
because they logically belong together.
There is no "global cycle" in MatPLC unless the user specifically
configures one. By default, all modules run asynchronously, with semaphores
making sure they don't step on each others' toes.
Explanation from a PLC background: the MatPLC reduces scan time at the
expense of latency - at the top/bottom of the scan, it simply uses the
latest available values rather than waiting for fresh ones. This is by
Using synch, the user can configure a global scan which interleaves
scans of the ladder with refreshing the I/O, classical PLC style.
For modules like a modbus slave, one would normally leave it
asynchronous, serving requests as they come in.
Similarly for any other modules that don't really belong in the global
cycle. Perhaps they might even have a mini-global-cycle of their own - for
instance, an I/O module and a corresponding DSP module might be synched
together but not to anything else.
Option 1: no synch configuration
Subsection not yet written.
Option 2: simple synch configuration
Subsection not yet written - see the comments in the example config file in
Option 3: advanced synch
Subsection not yet written; however, there is an example, and some comments in the
other example config file in demo/basic_synch.
$Date: 2005/12/08 09:13:44 $