ATI
Q46UV UV254/Turbidity Monitor
Part 5 - Configuration
33
O&M Manual
Rev-D (11/19)
PID Setpnt
The measured value which the controller is attempting to maintain by
[Iout1=PID]
adjusting output value. It is the nature of the PID controller that it never
actually gets to the exact value and stops. The controller is continually
making smaller and smaller adjustments as the measured value gets
near the setpoint.
PID Prop
Proportional gain factor. The proportional gain value is a multiplier on
[Iout1=PID]
the controller error (difference between measured value and setpoint
value.) Increasing this value will make the controller more responsive.
PID Int
Integral is the number of “repeats-per-minute” of the action
[Iout1=PID]
of the controller. It is the number of times per minute that the controller
acts on the input error. At a setting of 2.0 rpm, there are two repeats
every minute. If the integral is set to zero, a fixed offset value is added to
the controller (manual reset.) Increasing this value will make the
controller more responsive.
PID Deriv
Derivative is a second order implementation of Integral, used to supress
[Iout1=PID]
“second-order” effects from process variables. These variables may
include items like pumps or mixers that may have minor impacts on the
measured value. The derivative factor is rarely used in water treatment
process, and therefore, it is best in most cases to leave it at the default
value. Increasing this value will make the controller more responsive.
Set 4 mA
These functions set the main 4-20 mA output for the transmitter. The
Set 20 mA
20 mA output value for UVA should not be set higher than 1.300.
[Iout1=UVA]
The value stored for the 4 mA point may be higher or lower than the
value stored for the 20 mA point. Use the LEFT arrow key to select the
first digit to be modified. Then use the UP and LEFT arrow keys to
select the desired numerical value. Press ENTER to store the new
value.
*Set 4 mA #2
These functions set the second 4-20 mA output for the transmitter. The
*Set 20 mA #2
output may be set to track temperature (default). Turbidity (NTU), UVA
[temp/D.O.]
or DOC (mg/l). The values stored for the 4 mA point may be higher or
lower than the value stored for the 20 mA point.
The 4 mA and the 20 mA point must be at least 20 units away from each
other. Press ENTER to initiate user entry mode, and the value will flash.
Use arrow keys to modify value. Press ENTER to store the new value.
*Set 4 mA #3
OPTIONAL.
These functions set the optional third 4-20 mA output for
*Set 20 mA #3
the analyzer. The output may be set to track UVT, NTU, UVA, or DOC.
[temp/NTU/Aux]
The values stored for the 4 mA point may be higher or lower than the
value stored for the 20 mA point.
The 4 mA and the 20 mA point must be at least 20 units away from each
other. Press ENTER to initiate user entry mode, and the value will flash.
Use arrow keys to modify value. Press ENTER to store the new value.
