There are three solutions to measure voltages in the +/- 50V range:
1. Use an NI-4060 DMM which can measure signals up to the +/-300V. For higher channel count with the 4060 you can use SCXI with a switch module, SCXI-1127 or 1128.
2. You can use a DAQ MIO E-series card with an SC-2345 and the A10 SCC module. The A10 is a 10:1 attenuator module. Each A10 module has 2 input channels and can handle voltages in up to +/-100V.
3. You can use a DAQ MIO E-series card and an SCXI solution. The SCXI-1125 and the 1327 or 1313 100:1 attenutation terminal block, which gives you a range of +/-300V.
