Connecting Signals; Connecting An Analog Input Signal To A Single-Ended Input - Keithley DAS-800 series User Manual

Connecting Signals

Connecting an Analog Input Signal to a Single-Ended Input

This section describes how to wire signals to a DAS-800 Series board.
Although the illustrations in this section show a direct connection to a pin
on the main I/O connector, you will actually wire your signal to a screw
terminal on an accessory or expansion board or to a user-supplied, female
37-pin D connector. Appendix B lists the functions associated with each
pin on the main I/O connector.
The DAS-800 board contains both digital commons and low-level analog
commons. Use a digital common for all digital signal returns and power
supply returns; use a low-level analog common for all analog
signal returns.
The DAS-801 and DAS-802 boards contain digital commons, but no
dedicated low-level analog commons. If you are using all eight analog
input channels and all eight channels are configured for differential input,
you must connect a bias return path to a digital common instead of a
low-level analog common. If at least one channel is unused or configured
for single-ended input, you can use the negative side of the channel as a
low-level analog common.
When wiring analog input signals, it is recommended that you terminate
all unused input channels to low-level ground; this prevents the internal
amplifier circuitry from saturating if you select an unconnected input and
ensures the accuracy of your data.
Figure 4-8 illustrates how to connect an analog input signal to
single-ended analog input channel 0 on a DAS-800 board.
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