Turning an output on and off...

Possibly the time delay component is what you seek.

www.linuxcnc.org/docs/2.7/html/man/man9/timedelay.9.html

JT

racedirector wrote:

I used to have a system on my Mach3 install that flashed one of the outputs of my breakout board via a bd679 "relay" and now I want to do the same with LinuxCNC, Can anyone point me to any docos or ways of possibly creating timers to flash different sequences due to different states in LinuxCNC like, pausing, tool change requests, VFD errors or driver errors etc?

What sort of flash-codes did you have in mind? What is the input signal?

Unless you are using a parallel port I would imagine that separate lights for each state would be easier. Or text entries in a GUI element.

It is relatively easy to change the frequency of a flash using HAL components, but anything more elaborate is probably easier in a custom HAL component. I can imagine mapping bit patterns from a MUX16 into the init pins of a shift register made from flipflops. But frankly that seems crazy.

racedirector wrote:

In Mach I used their macros to manage the state of Mach and then pulse the output of pin 16 which has a BD679 setup as a relay..

The LinuxCNC equivalent of a Mach3 macro is a custom component.

These can be written in C (for hard-realtime components) or Python (for userspace components).

Be aware that a reatlime component can't pause, halt, or wait. It has to run straight through every time, so the component structure would look a bit like

{define pins etc}

;;

If the input value has changed, change the flash pattern (int 32)

decrement the timer by the thread period
if the timer has expired:
shift the bit pattern right
set the LED output to bit 0
reset the timer

If you do it in Python then the timing will be less precise, but the code is allowed to wait/pause etc.

It sounds like you had a moderately complicated set of inputs to control the flash sequence?

racedirector wrote:

Just to add, it wasn't macros, it was a brain. Brains were basically AND/OR/IF/THEN gates that triggered from either STOP/PAUSE/ESTOP or input pins on the board. The resulting sum off all that was output to pin 16 in a series of pulses from timer objects.

Well, I would _still_ use a custom component, but you could do it with:

1: A mux_generic with as many inputs as you need patterns, and a U32 output controlled by your input logic.
2: Separate the individual bits from that mux into a second mux with bitslice
3: drive the second mux from a an updown component driven by a siggen clock output.

linuxcnc.org/docs/html/man/man9/mux_generic.9.html
linuxcnc.org/docs/html/man/man9/bitslice.9.html
linuxcnc.org/docs/html/man/man9/updown.9.html
linuxcnc.org/docs/html/man/man9/siggen.9.html