Gpio outputs

Good Day all,
I am trying to set up my classic ladder file and wish to turn some outputs on and off for testing.
Is it possible, to force an output on if it is in the hal file?
Or must it be taken from the hal file, and use a M code greater than M100, then operate output through MDI.
Regards john

If it is not connected to a signal you can use setp.
linuxcnc.org/docs/2.5/html/hal/basic_hal...setp_a_id_sub_setp_a
For testing you can enter it from the hal configuration window.
linuxcnc.org/docs/2.5/html/hal/basic_hal.html

Rick G