BIG FAT WARNING:
This is pre-alpha code and information.
You assume all responsibility for its use.
DANGER: DON'T connect to a PLC unless you are certain it is safe to do so!!!
It is assumed that you are experienced in PLC programming/troubleshooting
and that you know EXACTLY what you are doing. PLC's are used to control
industrial processes, motors, steam valves, hydraulic presses, etc.
You are ABSOLUTELY RESPONSIBLE for ensuring that NO-ONE is in danger
of being injured or killed because you affected the operation
of a running PLC.
Also expect that buggy drivers could write data even when you expect that
they will read only !!!
PLC-Drivers provide a connection to external devices (PLCs, measuring devices).
Devices may be connected via serial interfaces or ethernet.
A PLC-Driver will be loaded at program start.
For each driver to load you need an entry in the configuration file
The Driver is executed in it's own parallell process (thread).
This makes sure that a driver waiting for a response from some device
will not stop the whole program while waiting.
The Threads share a common memory space.
The driver transfers blocks of data between the spreadsheet and the
A list of transfer instructions defines
address, size and direction of transfer for each block.
The file name of this list must be given on the respective line in
the configuration file.
The details of the file format are driver specific.
The lists can be edited with a normal text editor.
All PLC drivers use blocks of data. The first and last element in PLC memory
are used to specify a block. For the corresponding area in the spreadsheet,
the first cell coordinate is specified. Further data elements are copied to
or taken from consecutive row of the same column.
Available PLC drivers: