3 output selection, 2 common problems and solutions – Cooper Instruments & Systems DFI 1650 Multi-Channel Digital Force Indicator User Manual
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CF 66
35
Rev. C 2/05
10.6.3 Output Selection
Jumpers located on the channel’s circuit board determine what outputs are generated when the value selected to
drive the Analog Output (from the DAC.CHANNEL and DAC.SOURCE menu items) equals the DAC.FULL SCALE
and DAC.ZERO SCALE settings.
Figure 10-3: Digital-to-Analog Output Jumper Locations
DAC.ZERO SCALE
DAC.FULL SCALE
J30
J31
Output
Output
jumper
jumper
CHANNELS WITH VOLTAGE OUTPUT
0-5V
2.5 Volts
5 Volts
open
closed
±5V
0 Volts
5 Volts
open
open
0-10V
5 Volts
10 Volts
closed
closed
±10V
0 Volts
10 Volts
closed
open
CHANNELS WITH CURRENT OUTPUT
4-20mA 4mA
20mA open
open
4-20mA 12mA
20mA open
closed
10.7 Troubleshooting
10.7.1 Error Messages
See “Error Messages” for information relating to error messages.
10.7.2 Common Problems and Solutions
Erratic Display
Check electrical connections for continuity and the transducer’s wiring code from its Certificate of Calibration.
Make sure that the load on the transducer is constant.
Check millivolt input to the (+)Signal (“+SIG”) and (-)Signal (“-SIG”) pins with a voltmeter.
+OVLD or –OVLD on Display
is overranging or underranging the amplifier circuit. Make certain all wires are connected properly.
If you remove all load from the transducer and you still see this message, the (+)Excitation (“+EXC”) or (-)Excitation
(“-EXC”) pins may be shorted to the (+)Signal (“+SIG”) or (-)Signal (“-SIG”) pins.
If you remove all load from the transducer and you get a numeric reading, the transducer may have a high zero
offset. Use the channel’s SETUP menu and set DIAGNOSTICS-DISPLAY ADC to “ON”; in the RUN mode this will
allow the [VALUE] button to display raw A/D readings as a percentage of its full-scale. If the raw A/D readings
display more than ±10% when there is no load on the transducer, the transducer has a high zero offset.