User`s manual

2.3 CONNECTING SIGNALS TO THE PCI-DAS1602/16
Use a C100FF-2 cable to connect to the board. The cable has a pair of 50-pin ribbon cable legs joined
together at a 100-pin header connector. You can use two CIO-MINI50 screw terminal boards to
terminate field signals and route them into the PCI-DAS1602/16 with the C100FF-2 cable.
Analog inputs to the PCI-DAS1602/16 can be connected in three different configurations; these are
single-ended, floating-differential, and differential.
WARNING - PLEASE READ
Measure the voltage between ground at the signal source and ground at the PC. If
there is more than 10 volts, do not connect the
PCI-DAS1602/16
to this signal source
because you will not be able to make any readings. A voltage more than 30 volts will
likely damage the board or the computer. A voltage this high can also be hazardous
to your health.
2.4 ANALOG INPUT CONNECTIONS
2.4.1 Single-Ended
Single-ended inputs are most appropriate in systems where the signal source and the data acquisition
board share a common ground. This is a very common scenario and includes almost all systems where
the data acquisition system is supplying either the power (+5V and GND) or the excitation (from a D/A).
In this case you can take advantage of the PCI-DAS1602/16’s 16-channel mode without affecting
performance.
Single-ended inputs are also useful the signal source is electrically isolated (also referred to as floating)
from the data acquisition board’s ground (e.g. connecting to the two terminals of a battery). However, the
use of differential input configuration will provide better noise immunity than single-ended when
monitoring an isolated signal source. Unless you absolutely need more than eight channels, we
recommend using the differential input mode for isolated input signals.
Please refer to the next paragraph for connection information for the connection of isolated signals to
differential inputs.
.
2.4.2 Floating Differential
A floating differential input is two wires from the signal source and a 10K ground reference resistor
installed at the PCI-DAS1602/16 input. The two signals from the signal source are Signal High
(CH# High) and Signal Low (CH# Low).
The reference resistor is connected between the PCI-DAS1602/16 CH# Low and Analog Ground pins.
This floating configuration is appropriate when the signal source is floating with respect to ground, (e.g.
a battery or 4-20 mA transmitter), the lead lengths are long, your system is subject to substantial EMI
interference.
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