Cooper Instruments & Systems DFI 1650 Multi-Channel Digital Force Indicator - Manual (Page 50)

CF 66 44 Rev. C 2/05
Step 3: Move the LVDT’s armature to the position that displays the lowest value of raw analog-to-digital converter
readings (i.e. a number close to 00.000%). This is the LVDT’s electrical null.
Step 4: Firmly clamp down the LVDT’s body.
Step 5: Move the LVDT’s armature to roughly the position you wish to define as “positive full scale”. If the
displayed analog-to-digital converter reading is a negative value, you must swap the wires connected to the
(+)Signal and (-) Signal pins (labeled as “+SIG” and “-SIG”) on the channel’s 12-pin connector to make the reading
positive.
11.7 Analog Output Configuration
11.7.1 Identifying the Output Type
An AC/AC-LVDT Input channel is available with one of two types of digital-to-analog (DAC) outputs: voltage or
current. You can determine which type of output a channel has by one of three ways:
• Consulting the instrument’s System Calibration Sheet.
• Examining the SYSTEM MENU->CONFIGURATION->CHANNEL nn TYPE menu item where nn is the number
of the channel. If the channel’s type is AC-AC LVDT V, it has a voltage output. If the channel’s type is AC-AC
LVDT I, it has a current output.
• Examining the channel’s circuit board as shown in the figure below.
11.7.2 Channel Menu Items
The Analog Output can be driven by any channel’s track, peak or valley value.
See the “Channel Menu” section earlier in this chapter for a complete listing of SETUP menu items available on the
DAC.SETUP sub-menu.
11.7.3 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 11-2: 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