[Emc-users] Possible MESA 5i20 problem

[Leonardo M. <ldm...@gm...>]

Hello to all!

I have a camshaft grinder wich is working with a MESA 5i20 for 8 years more
or less. Never had a problem until recently.

A couple of days ago I had a major failure on the PC (not the power supply)
so I replaced the complete unit to put the machine to work and then repair
the other one.

I also had a failure on one of the stepper drivers (probably the output
stage since it's oscillating when I try to move it).

It's more than likely that all these fails ocurring at the same time have
the same source wich I believe could be a short circuit due to coolant
vapour inside the cabinet.

Anyway, I installed the new PC and new driver and everything seems to work
fine except that from time to time I have two outputs activated when I
activate only one. More precisely, when I try to jog the spindle (I don't
have a VFD is a two speed 3 phase induction motor with contactors) the
output jogs the spindle as usual but also, the electrovalve that moves the
hydraulic pivot the machine is activated/deactivated.

Looking into hal, there's no activation in the LinuxCNC virtual pins, but I
do get an activation from the 5i20 output port. I changed the physical
output ports of the 5i20 to try the other connector and I still have the
same erratic behaviour.

I re installed LinuxCNC with the last wheezy .iso and the problem showed a
few times. Now it's working ok, but from time to time the problem appears.

I suspect this is an FPGA related problem may be? Or with the resistors at
the output?

Thank you as always!

Leonardo Marsaglia