I read the pdf with google translate and I don't find chronogram or something like that. Can you ask the developper ?

Dear Jerome,
the developer said he knows from other users, that the have some time problems with software which sends the signals faster than 10us each signal. That means for example the high signal must be given from the software >=10us before ther next signal is sended. In the knew version of the board they changed the pulse/signal transmitter (optokoppler) from PC817 to a faster one (PC847) to avoid this problems. But this will not help me with the old version :-(.
Best regards
Frank

What is the external timer frequency ?

I don´t use an external timer. If I understand the support from GWR right, there isn´t a special protokol. The direction is conrolled by a high or low signal on a dedicated pin for each motor of the parallel port. For the motor rotation one impulse on on a dedicated pin for each motor is one step. But the pulse duration/pulse width (high or low) should be longer (>10us).
Best regards
Frank

Do you try MaxCom_XP.dll ?

I tested the MaxCom_XP.dll with manual movement. The motor makes a very slow movement. If I increased the cutting speed, the movement was faster. But the way of manaual movement was only about 1mm instead of 50mm I typed in. The NB mm / pas value is right configured.
I talked to GWR again. They will send me a new PC847 optokoppler chip next week. Hopefully the problem is solved than.
Best regards
Frank

[quote=Frank]
But the way of manaual movement was only about 1mm instead of 50mm I typed in. The NB mm / pas value is right configured.
[/quote]

Do you see your motors lost steps ?

With MaxCom_XP.dll the motor lost no steps.
Frank

So, you don't still have problem with your CNC board, do you ?

With the MaxCom_XP.dll the motor movement is not correct. It moves only about 1mm instead of 50mm. If I got the new optokoppler chip I test it and give you a status.
Frank