A2.5 Digital Follower/Analog Ratio, Mode 3; A2.5.1 Digital Reference Signal; A2.5.2 Analog Ratio Signal; A2.5.3 Mode 3 Parameters - Seco DS9000 Installation & Operation Manual

To summarize, the following items must be known or calculated:
A). Desired MOTOR RPM with full input signal, and Ratio (PS1 – PS4) at 1.000.
B). Pulse rate (PPR) of digital tach on controlled motor.
C). Desired READOUT when motor is running at speed produced with full input signal.
D). Minimum and Maximum ratios required or allowed.
From A), calculate FED1 as follows:
FEd1 = (4096 x (MAX INPUT VOLTAGE/10 VOLTS))/30
Enter B) as parameter FEd0
Enter C) as parameter SCF1, using SCd1 to set decimal point if required.
Enter Minimum ratio as parameter LO, and Maximum ratio as HI.

A2.5 DIGITAL FOLLOWER/ANALOG RATIO, MODE 3

A2.5.1 DIGITAL REFERENCE SIGNAL

The DIGITAL REFERENCE signal in this operating mode is a frequency signal or pulse train,
maximum 5 Volts P-P, and with frequency for full speed in the range of 50 Hz to 18 kHz. An analog
signal 0-10 VDC, 4-20 mA, or a speed potentiometer is used to set the RATIO values.
The DIGITAL REFERENCE signal is input on TB1, terminals 11 and 12. See DS9000 I.M., Figure 2.9
for details. An example of a "Follower System" with two Bronco II's is shown in the DS9000 I.M. in
Figure 4.1.

A2.5.2 ANALOG RATIO SIGNAL

The ANALOG RATIO signal is fed into the DS9000A via the DB9 connector on the rear. Connection
points are specified in Section 2.2.3.
Instead of an external signal, a speed potentiometer may be used to provide an ANALOG RATIO
signal. Connection points would be:
Clockwise terminal -
Wiper (Center terminal) -
Counter-Clockwise terminal - PIN 3 (COMMON)
The Speed potentiometer resistance value should be 2K to 10K, 2 watt. A 10 turn potentiometer is
highly recommended due to the fine resolution and high accuracy of the DS9000A.
A2.5.3 MODE 3 PARAMETERS – Parameters used in this mode include the following:
LO – Sets the RATIO at minimum input signal.
LO may be set from 0 to the value of HI. Default setting is 0.000.
HI – Sets the RATIO at maximum input signal.
HI may be set from LO to the value of 9.999. Default setting is 1.800.
FEd0 – Sets the FEEDBACK RATE of the controlled motor.
FEd0 is set for MAXIMUM FEEDBACK FREQUENCY in Hertz
((RPM x PPR)/60) divided by 30. See the DS9000 I.M. Section 4.1.1
A10
PIN 9 (+10VDC)
PIN 4 (REFERENCE)