CONTREX MLP-Trim - Manual (Page 77)

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Follower Mode Analog Setpoint Example
The following example demonstrates Follower mode scaling using analog setpoint:
A pump delivers 20.0 gallons per minute of ingredient A when the pump
motor rotates at 1750 RPM. A second pump delivers 60.0 gallons per
minute of ingredient B when the pump motor rotates at 1750 RPM. A
potentiometer connected to the analog input of the MLP-Trim produces
a 10.0 volt signal when the pump B and pump A motors rotate at 1750
RPM. The lead motor A has an encoder feedback of 1000 PPR. The
feedback motor is equipped with a 60 tooth ring kit sensor. The
Follower Setpoint 1 is to reflect the flow ratio in gallons/minute of
ingredient B to ingredient A.
Table 3-27 Follower Mode Setpoint Allocation
CP Parameter Name Value Remarks
CP-84 Analog Input
Allocation
CP-21 Follower
Engineering Units
CP-34 Max RPM Feedback
CP-31 PPR Feedback
CP-33 Max RPM Lead
CP-30 PPR Lead
Allocates the analog input as the
Follower Setpoint 1.
This is the Engineering Unit value
that is present if the analog input
were at 10.0 volts and the lead and
feedback at max RPM.
60.0 gal/min (ingredient B) = 3.000
20.0 gal/min (ingredient A)
The maximum operating RPM of
the feedback shaft.
The resolution of the feedback
sensor.
The maximum operating RPM of
the lead shaft.
The resolution of the lead
sensor.
6
3.000
1750
60
1750
1000