Hi Andrea,
I looked at this <a href="http://www.riegler.net/PDF_ENG/wika/pe8101e.pdf" target="_blank">Pressure Transmitter</a>
it seems to be a WIKA S-10, I?m not familiar with how a pressure transducer
works but something that I can tell you from the spec sheet is that: seems that
you can have different versions of the sensor 2 wire, 3 wire and current or
voltage output, I would suggest connecting your sensor in a voltage mode since
the other way you will have to add a shunt resistor.
Most of the time those sensor have three wires, red, black
and white, you will set your connection for differential where red goes to AI+,
black to AI- and white to AI GND and taking into account that white is the
ground. As long as you output does not exceed what we spec -/+ 10 volts, <a href="http://www.ni.com/pdf/manuals/370969b.pdf" target="_blank">6015</a>
Let me know if it helps