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Alicat P Series Pressure Gauge User Manual

Page 36

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value to register 22. For example, if you wished to try a “D” term of 25, you

would type *W22=25 followed by “Enter” where the bold number denotes the

new value.
The computer will respond to the new value by confirming that 22=25. To

see the effect of the change you may now poll the unit by typing A followed

by “Enter”. This does an instantaneous poll and returns the values once. You

may type A “Enter” as many times as you like. Alternately you could resume

streaming mode by typing *@=@ followed by “Enter”. Repeat.
You may test your settings for a step change by changing the set-point. To do

this type A32000 (A is the default single unit address, if you have multiple

addressed units on your RS-232 / RS-485 line the letter preceding the value

would change accordingly.) followed by “Enter” to give the unit a ½ full scale

set-point. Monitor the unit’s response to the step change to ensure it is

satisfactory for your needs. Recall that the “P” term controls how quickly the

unit goes from one set-point to the next, and the “D” term controls how quickly

the signal begins to “decelerate” as it approaches the new set-point (controls

the overshoot).