The E Series boards (6070E) use the DAQ-STC chip for the 8 digital lines of port 0, which consists of +5 V connected to a 50 kOhm pull-up resistor. This is hard wired within the board and cannot be disabled.
If you cannot work around this with your external circuitry, you may need to get a different board with user-defined pull-up/down capability.
PC-DIO-24/96 - User-defined* 100 kOhm
NI-6013/6014 - Pull-down 1.5 kOhm
NI-6533/6534 - User-defined* 100 kOhm
AT-MIO-16D - Pull-up 100 kOhm
PC-LPM-16 - Pull-up 10 kOhm
DAQCard-700 - Pull-up 10 kOhm
E-Series - Pull-up** 50 kOhm***
The DIO-24/96 family allows jumper-selectable pull-up/pull-down configuration. The NI-6533/6534 family of devices similarly allows the
user to configure pulled up or pulled down DIO via the DPULL pin. See your user manual for more information.
**Digital lines 6 and 7 on the AT-MIO-16XE-50 also have pull-down resistors of 50 kOhms.
***The extended digital lines on the 6025E, AT-MIO-16E-10 and AT-MIO-16DE-10 have 100 kOhm pull-up resistors
