Modbus devices control

That would be a lot of com ports on a pc.  Can you instead give each of the
units an IP address and use modbus over an ethernet or something similar?

You can use a simple PC, given the right programming.  I can't point you to
the right programming.  You may find that standard laboratory packages have
some provision for this.   You can code your own.

The reason a lot of applications are in VB is that it is easy to learn and
work with.

Michael

Herman Family ha scritto:

Thanks for your reply!
Could you point me to some software package? I read about LabView, is it
good?

proclaimed to the world:


Labview is not really for control of industrial machines. Can you tell
us more about the application?

Does it run all the time?
Is material loaded into the process or machine?
How fast is the process?

Paul M ha scritto:

The machine is supposed to run for a production cycle and then be
switched off for a while. Material is loaded in it, about every few
months or so. The process should be a couple of hours.

may be that he has modbus-rtu devices ; if he has modbus-over-ethernet
then the task is easier, yes.

but there seems to be plenty of modbus implementations around, just look at
http://freshmeat.net/  and search for modbus,
http://freshmeat.net/projects/libmodbus/
might be one good example..


yes, mostly depending on programming skills .. or about any sw house
can be contracted to do this kind of work, this is no rocket science.

having one more plc in between might help so that the computer doing the
vpn would need to interface only one plc that in turn would speak modbus
to rest of the controllers or whatever-modbus-speaking-devices there may be.
Having a real plc instead of 6-port serial card is expensive tough but
it might pay itself back if the programmer doing the pc-plc -link may
do it in modbus-over-ethernet and with single plc ; someone will then need
to program that gateway-plc to distribute the configuration items to
real conrollers .. requires some thinking and coding anyway..


smells like a holy war coming.. :-)

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John.John ha scritto:

I've found this on freshmeat.
http://www.tuxplc.net/index.php?page=datalogging-application
I think this will work for me.
Has anyone had any experiences with it?
Thanks to all who answered my posts.

cheers!