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Watlow Series 935A User’s Manual
Choose the PID Strategy
You may rely solely on the Auto-tune
[`Aut]
function (p. 32) and factory defaults to determine PID values for your system, or you may
use auto-tuning and additional manual adjustments. You must select dead band
[``db]
and calibration offset
[`CAL]
values manu-
ally.
The Series 935A PID Menu is the first sub-menu you encounter after moving to the Operations Menu. The PID Menu provides a soft-
ware location to select the individual heat or cool proportional band, hysteresis, and cycle time values; and the dead band, integral,
derivative, and calibration offset values.
To go to the PID Menu:
1.
Go first to the Operations Menu by pressing
.
and
,
simultaneously for three seconds.
2.
Scroll through the Operations Menu with
,
until you see the
[`Pid]
prompt.
3.
While pressing
ß
to display
[``no]
, choose
[`YES]
with
.
or
,
.
4.
Release
ß
to see the first PID prompt.
NOTE: Access to the PID Menu and the prompts there varies with lockout function and output set-up. The PID Menu is
locked out when the 935A leaves the factory.
•
Lockout function; the Lockout Tag
[`tAg]
function masks menus from view (if you cannot see a prompt, you can make no
change). See Using Lockout Functions, p. 18.
•
Output set-up; you must choose
[hEAt]
or
[COOL]
in either Output 1 or Output 2 to have access to the PID Menu. With a
[hEAt]
only choice,
[COOL]
prompts are not visible, and vice versa. See the Valid Output Functions Table, p. 3, or Setting Up Inputs and
NOTE: Proportional Band, Integral, Derivative, Dead Band, and Calibration Offset values are adjustable in whole or tenth
°F or °C, depending on input type
[``In]
and
[`C_F]
Celsius/Fahrenheit Configuration Menu choices.
Learn the PID Menu
