2
DITAK 3D TIME BASE SETTING PROCEDURE
The Time Base is set by adding 12 binary increments from 0.001 second to
2.048 seconds. This is done by setting the switch for each increment to be added
to the “ON” (UP) position. To determine the increments required, use the
folowing procedure.
Start by selecting the first increment which is greater than half the desired
time base and add subsequent increments that are more than half the difference
needed.
EXAMPLE: A Time Base of 1.745 seconds is set as follows.
Start with 1.024 (1.745 - 1.024 = 0.721 sec needed)
Add 0.512
Total 1.536 (1.745 - 1.536 = 0.209 sec needed)
Add 0.128
Total 1.664 (1.745 - 1.664 = 0.081 sec needed)
Add 0.064
Total 1.728 (1.745 - 1.728 = 0.017 sec needed)
Add 0.016
Total 1.744 (1.745 - 1.744 = 0.001 sec needed)
Add 0.001
Total 1.745 seconds, Desired Time Base
For Time Bases, greater than 4.095 seconds but less than 8.190 seconds, set
up ½ the required Time Base as above and set the X2 multiplier to on. For Time
Bases greater than 8.190 seconds but less than 16.380 seconds, set up ¼ the
required Time Base and set the X4 multiplier switch on. Use the same
procedure to multiply X8 for Time Bases up to 32.76 seconds.
At least one of the four Time Base Multiplier Switches must be “ON” (UP)
for operation. If more than one is “ON”, the unit will not function properly.
When the Time Base is less than 4.095 seconds, X1 multiplier switch must be
turned “ON”.
Note: Turning “ON” the FREQUENCY DOUBLING FUNCTION will decrease
the required Time Base to ½ the time normally required.
Turning “ON” the Decimal Point switches will increase the required time
base by multiples of ten.
In this example an existing timing belt pulley, in the drive train of a set of
nip-rolls, is used to excite an inexpensive magnetic pickup. Direct readout is
obtained by setting the time base to a period in which the number of teeth
passing the pickup is numerically equal to the desired readout number. This
can be worked out in logical steps as shown in the example below, but in this
case the formula at right can also be used:
Time Base (seconds) =
60 x (Numerical Readout Desired) x DDP
-¾-¾¾¾-
(Pulses per rev.) x (RPM of gear)
A turbine type flow meter uses a magnetic pickup to sense passing turbine
blades, and has a calibration factor of 677.8 pulses/gallon of fluid passing
through. It is to be used with a DITAK 3D to read directly in gallons/min in
1/100ths at flow rates to 50 GPM. The following logical steps can be used to
determine the time base setting required for direct reading:
At 50 GPM, output pulses will be -
50 GPM x 677.8 pulses/gallon = 33890 pulses/min.
At this flow rate the desired reading is 50.00 GPM. Set D.P.2 switch “ON”
and use Display Decimal Point value of 100.
Time Base (seconds) =
= 8.852 sec.
If frequency doubling is used, this time base can be further divided by 2, or
8.852/2 = 4.426 seconds.
Since this is a longer time than can be achieved by adding binary
increments alone (with X1 multiplier) it will be necessary to set the time base
at ½ the desired value and then turn “ON” the X2 multiplier switch.
4.426 = 2.213 (Binary Setting) x 2 (multiplier setting)
60 x 50.00 GPM x 100 (DDP)
¾¾¾¾
33,890 pulses per minute
1. USING EXISTING MACHINE GEAR OR SPROCKET FOR SIGNAL GENERATION & CALCULATING TIME BASE FOR DIRECT READOUT
2. DETERMINING TIME BASE IN A FLOW RATE APPLICATION
Switches set-up for a 1.745
sec. time-base per example
DITAK 3D TYPICAL APPLICATIONS
DDP = Display Decimal Point
0 = 1
0.0 = 10 = D.P.1 “ON” up
0.00 = 100 = D.P.2 “ON” up
= = 1.907 sec.
The procedure for setting the additive time increments to obtain this time
base is shown above. Note: The time base can be halved if FREQUENCY
DOUBLING is used.
60 x 723 ft/min x 1
¾¾¾
14 PPR x 1625 RPM
TROUBLESHOOTING
For further technical assistance, contact technical support at the appropriate
company numbers listed.
ORDERING INFORMATION
PART NUMBERS FOR AVAILABLE
MODEL NO. DESCRIPTION SUPPLY VOLTAGES
230 VAC 115 VAC
DT3D 5-Digit Programmable Tach. DT3D0510 DT3D0500
For more information on Pricing, Enclosures & Panel Mount Kits refer to the
RLC Catalog or contact your local RLC distributor.