Daniel,

I'm sure you are right as the manual promises around 0.4V for the output low voltage and thats what the other outputs have or less. Some other weird behavior with the pin 17 when the safety chage pump is set OFF as then the high voltage is only around 2.8V but low voltage is OK. I just wonder how folks have been able to use this card or perhaps they only needed a good high logic 1 and for low voltage just something which is 'not 1.'

Risto,

I think we could be having a communications problem.  When you say SCHP on/off, it may not be clear if you refer to the software or the hardware.  I will try to briefly summarize how this is supposed to work:

If using the SCHP, enable it in the software (enable SHCP on pin 17, port1) and set the jumper on the board to SCHP on. When the SCHP is enabled in the software (Mach3 out of reset) on the terminal for pin 17, you should measure +5vdc, when the signal goes off (reset), it should go to 0.  This is setup this way, so you can use the output of this pin to enable other external devices.

If not using the SHCP, make sure it is disabled in the software; otherwise it will continue sending a pulse stream (that would explain the voltages you are measuring).   If the jumper is set to off, terminal will behave like any other pin, it will send whatever is mach3 is sending.

If this still does not explain what is going on, please let me know, and I will send a wiring diagram for you to test a couple of voltages to see if the microcontroller is working ok and the test the signals as they pass through the buffers and optos.

My only explanation for you getting voltages between 1.6 and 2.8 is that the SCHP is on in the software and the jumper is set to have the SCHP on in the hardware. Those signals come straight out from a buffer.

Please also check that in the configuration window, the option for having the SCHP enabled during reset is off.

Thanks,

Arturo Duncan
http://cnc4pc.com

When I had the SCHP jumper set to OFF (1-2) position on the board I got a good 0V level and but 2.8V for the high. After I set the Charge Pump off in Mach as well I get good levels for both low and high so this works fine.  Also the STEP and DIR pulses (5us) for the axis show very good levels and sharp wave forms with oscilloscope even at 100kHz Kernel speed (2.8GHz Intel Mother board) so I'm confident that we can sort the remaining prb out too with your support.


Regards,
Risto