Dwyer 275 - Manual (Page 6)

In order to make the valve stem move fast, push <ENTER> with
<UP>, or <DOWN>.
5. Push <ESC> and MANUAL mode is displayed.
Parameter Mode (PARAM)
Parameter types
There are four types in Parameter mode: Dead Zone, KP, KI, and KD.
These values are reflected as soon as they are changed, therefore the
appropriate values are found by checking the valve’s motion in real time.
Dead Zone (dEAdZONE)
This is the range of error % that the positioner is not adjusted. Hunting
or oscillation due to friction between the stem and packing is prevented
by this parameter.
KP
This is a proportion constant value that is correcting by error %. If this
value is too big, there can be hunting, even though it finds position by the
input signal. If the value is too small, accuracy gets worse.
KI
This is an integral constant value adding or subtracting the correction
that is corrected error % on the previous correction signal. If this value
is too big, there can be oscillation. If it is too small, the time to find the
exact position increases.
KD
This is a differential constant value adding the previous correction signal
with the changing correction signal by the error % change rate.
Adjustment of Parameter
Dead Zone (dEAdZONE)
1. Push <ENTER> at RUN mode for 6 seconds and AUTO CAL message
appears.
2. Push <DOWN> twice and PARAM mode is displayed.
3. Push <ENTER> and dEAdZONE mode is displayed.
4. Push<ENTER> again and *EAdZONE message appears.
5. Adjust dEAdZONE value by pushing <UP> or <DOWN>. Adjusted
value is applied immediately without additional operation. Users can
easily check its adjustment by changing the current input signal to the
positioner. Optimum control value is found by adjusting values during
valve operation.
6. Push <ENTER> to save the value. +EAdZONE message appears on
LCD.
7. Push <ESC> three times to return to RUN mode.
KP
1-3. Adjustment method and procedure same as dEAdZONE.
4. Push <DOWN> at dEAdZONE mode and KP mode is displayed.
5. Push <ENTER> and *KP message appears on LCD.
6. Adjust KP values with <UP> or <DOWN>. Adjusted value is applied
immediately without additional operation. Users can easily check its
adjustment by changing the current input signal to the positioner.
Optimum control value is found by adjusting values during valve
operation.
7. Push <ENTER> to save the value. +KP message appears on LCD.
8. Push <ESC>.
9. Push <ESC> twice to return to RUN mode.
page 6
Push <UP>.
Push <UP> + <ENTER> at the same time.
Push <DOWN>.
Push <DOWN> + <ENTER> at the same time. Valve stem moves up slowly.
Valve stem moves up quickly.
Valve stem moves down slowly.
Valve stem moves down quickly.
Button operation for valve stem movement
(1) Push <ENTER> for 6
seconds. (2) Push <ENTER>. (3) Push <ENTER>.
(4) Push <UP>, <DOWN>. (5) Push <ESC>. (6) MANUAL MODE.
(1) Push <ENTER> for 6
seconds. (2) Push <DOWN> twice. (3) Push <ENTER>.
(4) Push <ENTER>. (5) Push <ENTER>
after adjustment by
<UP>, <DOWN>. (6) Push <ESC>.
(7) Push <ESC> twice. RUN MODE.
(1) Push <ENTER> for 6
seconds. (2) Push <DOWN> twice. (3) Push <ENTER>.
(4) Push <DOWN>. (5) Push <ENTER>. (6) Push <ENTER>
after adjustment with
<UP>, <DOWN>.
(7) Push <ESC>. (8) Push <ESC> twice. RUN MODE.