Problem with Boxford TCL lenze controller

[John11668]

John11668,

I have recently had a problem where my spindle started unexpectedly after the LinuxCNC PC closed down when I didn't expect it to. I suspect it was the cheap Chinese BOB that closed it's relay with the lack of a definite ON or OFF voltage from the computer. I plan to add an interlock switch to the spindle control which will interrupt the line from the relay and protect against spurious starts during tool changing.

Hi Kitwn
I can own up to having a cheap chinese board (one of several)
If I shut down Mach3 the spindle pulses .
With the same board I shut down Linux cnc and the spindle runs, and would run forever unless I turn off the mains to the machine. The only difference is that Mach runs through a UC100 controller but the computer is switched off .
Linux runs through PP but once again the computer is off.
When I switch on the relay light on the Bob is illuminated.

[Kitwn]

Hi Kitwn
I can own up to having a cheap chinese board (one of several)
If I shut down Mach3 the spindle pulses .
With the same board I shut down Linux cnc and the spindle runs, and would run forever unless I turn off the mains to the machine. The only difference is that Mach runs through a UC100 controller but the computer is switched off .
Linux runs through PP but once again the computer is off.
When I switch on the relay light on the Bob is illuminated.

It might be possible to prevent this problem by fitting a resistor somewhere on the BOB to pull the relay control line to ground but without a circuit diagram it would be difficult to work out where it should go. Under normal working conditions you don't expect the PC to shut down suddenly but a safety interlock for tool changing is definately a good idea. I'm sure there is a discussion about this on the forum from a year or two back.