Cooper Instruments & Systems DFI 1650 Multi-Channel Digital Force Indicator - Manual (Page 46)

CF 66 40 Rev. C 2/05
This menu item doesn’t change the mathematical scaling of the channel’s values; that can be changed by altering
the “CALIBRATION DATA-KNOWN POINT X/Y” menu items and then performing a re-calibration.
When a character position is flashing press the [UP] or [DOWN] button to change the character. Press [ENTER] to
advance to the next character.
DISPLAY.AVERAGE Menu Item
Controls the speed with which the channel’s display values will update. Display averaging does not affect the
channel’s analog output or its peak/valley detection, which will proceed at the speed selected by the “OPERATION-
FREQ.RESPONSE” menu item. The choices are:
• “ON” means that the display will update four times each second. The channel’s values will be averaged for ¼
second, then displayed.
• “OFF” means that the channel’s display will update as quickly as possible.
11.5.3 AUXn FUNCTION Menu Items
The AUX1 FUNCTION and AUX2 FUNCTION menu items determine what happens when the Auxiliary Function
pins (labeled as “AUX1” and “AUX2”) on the channel’s connector are activated. These pins are “activated” when
they are connected to the DGND pin. The choices are:
• “DISABLED” means that activating the pin does nothing.
• “TRACK HOLD” means that the tracking, peak and valley values will not be updated.
• “HIGH/LOW HOLD” means that the peak and valley values will not be updated.
• “HIGH/LOW CLEAR” means that the peak and valley values are reset.
• “TARE ON” activates the channel’s Tare function (resets it to zero).
• “TARE OFF” deactivates the channel’s Tare function.
As the Auxiliary Function pins are not isolated, it is recommended that a push-button switch or relay is used to
connect these pins to the DGND pin.
11.5.4 CALIBRATION TYPE Menu Item
The choices for this menu items are:
• “TYPE=2 POINT CAL” means 2-Point Known Displacement Calibration. You are prompted to apply the
displacements to the transducer that were entered in the “KNOWN POINT ½” and “KNOWN POINT 2/2”
registers. This technique assumes that the transducer is linear throughout the entire stroke, so the usual
displacements used are zero scale and full scale.
• “TYPE=3 POINT CAL” means 3-Point Known Displacement Calibration. You are prompted to apply the
displacements to the transducer that were entered in the “KNOWN POINT 1/3 and “KNOWN POINT 2/3” and
“KNOWN POINT 3/3” registers. This technique can be used to compensate for the different sensitivities that an
LVDT may have on each side of its electrical null. The usual displacements used are zero scale, half scale and
full scale, but you are not restricted to these displacements.
• “TYPE=5 POINT CAL” means 5-Point Known Load Displacement Calibration. You are prompted to apply the
displacements to the transducer that were entered in the “KNOWN POINT 1/5, “KNOWN POINT 2/5”, “KNOWN
POINT 3/5”, “KNOWN POINT 4/5” and “KNOWN POINT 5/5” registers. This technique can be used to
compensate for the non-linearity in the transducer as well as the different sensitivities on each side of its
electrical null. The usual displacements used are zero scale, on-quarter scale, half scale, three-quarters scale
and full scale, but you are not restricted to these displacements.
The selection of the calibration type affects what menu items appear in the CALIBRATION DATA sub-menu.
11.5.5 CALIBRATION DATA Sub-Menu
This sub-menu enters the values that will be used by the instrument when it calibrates itself to the transducer. The
menu items that are displayed will change according to what the CALIBRATION TYPE is set for.
FULL SCALE VRMS Menu Item
The transducer output when its full-scale displacement is applied to it, in Volts RMS (root-mean-squared) assuming
3 VRMS excitation. This menu item is used by the instrument to set gain of its amplifier circuit. This value is
normally found on the transducer’s Certificate of Calibration issued by its manufacturer.