PCLK2 not in HiZ on PC power up

[AdrianB]

I am using the PCI-DIO-32HS, and in the 653x user manual it states that this card should power up with all lines in high impedance (HiZ). However, this is not 100% true as PCLK2 outputs 5V when my PC boots up (all other lines seem to be fine). Is this due to the card being damaged, or have I inadvertently changed the power-up setting of my device? If so, how can I change it back.

I base my reasoning on a previous post which seemed to suggest this possibilty, i.e. changing the power-up state of a device. Is this at all possible?

Thanks for the help

[Jeremy_C]

Adrian,
You are correct in that all of the lines should be in the high impedance state upon power up. By default, all lines should be pulled down. The way you change that is to connect either the DPULL (for data lines) or CPULL (for control lines) to 5V to pull up or GND to pull down. This is explained in Appendix D of the 653x user manual. If you are measuring 5V on PCLK2, try jumpering CPULL to GND and see if that forces PCLK2 to 0V.

653x User Manual

[AdrianB]

Hi Jeremy.
I have connected CPULL to +5V, meaning that the default state for all control lines should be high. However, this default state should not come into affect until my VI has been run, as on power up all lines are specified to be in high impedance (set as inputs). Using a DVM, it seems as if all lines (including PCLK1 and NOT PCLK2) are in high impedance as they all have a voltage that is within the TTL noise region. PCLK2 outputs 5V.

[Jeremy_C]

Adrian,
Connecting CPULL or DPULL should pull those specified lines to the desired voltage as soon as the board has power. It should have nothing to do with when your VI is executed. I verified this on my machine. I connected CPULL to +5V. As soon as the power supply of my computer turned on, both PCLK1 and PCLK2 were pulled to 5V. Also, without anything connected, PCLK1 and PCLK2 should be at the same level.