Cabl I Nb; Wire; Connection - HP 98640A Installation And Reference Manual

98640A Analog Input Interface
The wire termination receptacles on the wire termination assembly are arranged as shown in figure
2-3. You can open the throat of each receptacle by turning the screw above that receptacle counter-
clockwise (as viewed from above) with a small, straight-bladed screwdriver.
CABLING
Wire
Since the HP 98640A Analog Input Interface measures differential voltage there must be at least two
conductors coming from the voltage source you will measure. Your voltage source should have its own
ground reference in any circuit that includes the interface. Where desired shielded cable may be used
for the hook -up. For easy hook up to the wire termination assembly, we recommend insulated solid
wire of any American Wire Gauge (awg) between 28 to 18 inclusive. Stranded wire may be used but
should be tinned with solder to hold the strands together.
Connection
NOTE
You must provide strain relief for the wires attached to
the wire termination assembly. The wire termination as-
sembly is not designed to support the weight of a large
cable or long lengths of individual conductors.
WARNING
THIS INPUT INTERFACE WILL APPEAR TO BE A
LOW-RESISTANCE PATH TO GROUND FOR ANY
VOL T AGE MORE THAN I 5 VOL TS ABOVE OR
BELOW GROUND.
WHEN POWER TO THE COMPUTER IS TURNED OFF
EACH INPUT IS SHORTED TO GROUND THROUGH
A ONE THOUSAND OHM RESISTOR REGARDLESS
OF THE VOLTAGE ON THE INPUT.
Open the throat of the receptacle where you will install a wire by turning the screw above the open-
ing counter-clockwise (as viewed from from above). Set the wire you will use in your strain-relief
device but leave enough slack to reach the termination assembly and allow for stripping the wire.
Strip between one-quarter and 9/32 inch (6 to 7 millimeters) of insulation from the end of the wire.
Insert the bare wire into the receptacle and turn the screw clockwise (as viewed from above) until the
wire is held firmly. Do not over tighten the screw as you may damage the termination block or the
slot in the screw's head.
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