When I connect an input to DI channel of USB 6501 card from my board which has sourcing Output t, iIn the Off state it is not pulled down properly. The volatge on the port in is 2.1V -2.5V based on the pull down resistor on my board. I suspect that it acts as a voltage divider.
The state on the card is still show as "HIGH "state, even my sourcing output driver has a pull down resister. when I use this interface board for PCI mseries devices it works fine. Do the pull down resister on my sourcing output is not worth. Is this because of pull up resister 4.7k inside USB card 6501.
USB 6501 specifications shows the Digital input accepts both source and sink modes. By default the card is in sourcing digital input mode. How do we can convert this in Sinkind digital input mode.
Could anyone Please give your suggestions to overcome this issue .
Thanks you.