Dwyer 2500 User Manual
Page 9
December, 1998
Page 9
949-1190-1
outputs. Set the value for the amount of temperature difference
between the turn off point (set point) and the turn on point. Only
appears if CY is set to ONOF.
Out
Fixed at ProP. For Current (Code 5) outputs only.
tunE
Tuning Choice: Select SELF or Pid.
SELF
The Controller will evaluate the Process and select the
PID values to maintain good control. The ramp function
(rt) can not be selected while SELF tunE is active. The
temperature descriptor will flash while SELF tunE is
active. The control will switch to Pid tunE when the
tuning function is complete.
Pid
Manually adjust the PID values. PID control consists of
three basic parameters, Proportional Band (Gain), Re-
set Time (Integral), and Rate Time (Derivative).
Pb
Proportional Band (Bandwidth). Select 5 to 5000 °F (3 to
2778 °C).
rES
Automatic Reset Time. Select OFF, 0.1 to 99.9 minutes.
Select OFF to switch to OFS.
OFS Manual Offset Correction Select OFF, 0.1 to 99.9%. Select
OFF to switch to rES.
rtE
Rate Time. Select OFF, 0.01 to 99.99 minutes, Deriva-
tive.
ArUP
Anti- Reset Wind-up Feature: Select On or OFF.
On
When ArUP is On the accumulated Reset Offset value
will be cleared to 0% when the process input is not within
the Proportional Band.
OFF
When ArUP is OFF, the accumulated Reset Offset
Value is retained in memory when the process input is
not within the Proportional Band.
rt
Ramp Time: Select OFF, 00.01 to 99.59 (HH.MM). When value
is entered, control calculates a ramp slope from the current
temperature to SP over the time entered. Changing rt or SP (or
pressing ENTER at either menu item) restarts the ramp function,
and re-calculates the slope. The right hand decimal point of the
lower display will flash while the ramp function is active. Self tunE
can not be selected while the ramp function is active. Selecting
OFF will stop a current ramp and drive the output as necessary to
reach set point
InPC
Input Correction: Select ±500 °F (±278 °C). This feature allows the
input value to be changed to agree with an external reference or to