Specifications for the Limit Switchs (home, forward, reverse, etc) is determined by the specifications of your NI motion controller PCI board. The UMI functions only as a pass through and breakout for the board .
The valid limit swich voltage for the PCI-7334 is 0 - 5 V. You will have to divide down a 12 V input before running it to the UMI and to your board. The 3.3k pull up resistor is only used to pull floating voltages to TTL levels and does not protect for high voltage signals.
Please note that the UMI-7774 provides optical isolation for limit switches and extended input levels (e. g. limit switch voltages: On = 3.5 to 30 V, Off = 0 to 2 V).
Best regards,
Jochen Klier
National Instruments Germany
