Ladder connections

Hello everyone, I´m new at linuxcnc

I would like to ask for a basic example/explantion on how to connect classicladder pins to parallel port pins.

finally , can i use a parallell port pin as input - output (bidireccional)?

many thanks in advance for your reply

As far as I know all parallel port pins are one way once the mode for that port is set in hal.

How to connect parallel port pins to Classicladder pins is the same as connecting any other pins in hal. You use a net command. One thing to remember parallel port hal pins naming is a little confusing because the port inputs are hal output pins and the port outputs are hal input pins. Nice and confusing but it makes sense if you think about it long enough. (A signal into the parallel port sends a signal out from the hal pin and vice-versa.)

So for example to connect an input from parallel port pin 10 the hal line might be (such as from a switch)
net ppsignal1 <= parport.0.pin-10-out => classicladder.0.in-00
And to out put a signal from the parallel port. (to trigger a solid state relay)
net ppsignal2 <= classicladder.0.out-00 => parport.0.pin-01-in

A net command in hal connects a "signal" (an arbitrary name you create) to a pin or pins. The signal name is the first thing after the net. If the signal name already exists the pin names after are connected. If it doesn't it is created... A signal can only be connected to one output pin, but can be connected to as man inputs as you like.

This has been a brief hal tutorial, there is a lot more in the manual. Please do your self a favor and read it.

Oh one more thing, Classicladder input and output hal pins are connected to the bit variables in CL like this:
hal pin classicladder.0.in-00 = %I0
hal pin classicladder.0.in-01 = %I1
hal pin classicladder.0.out-00 = %Q0
hal pin classicladder.0.out-01 = %Q1