Programming and operation, For ramp / soak feature, Theory of operation – Dwyer 1600 User Manual
Page 13: Program setup, Programming and operation for ramp / soak feature
Rev. 10/98
13
949-1239-3
PROGRAMMING AND OPERATION
FOR RAMP / SOAK FEATURE
The ramp / soak feature offers a great deal of flexibility by allowing changes
in the set point to be made over a predetermined period of time.
Theory of Operation
The 1600 Series controls offer a very simple approach to programming a
ramp. Rather than requiring the operator to calculate an approach rate
(usually in degrees per minute), the 1600 does the calculation internally.
Thus, the operator only needs to program the target set point, the time
desired to reach that point, and the time desired to hold at that point. When
the ramp segment is executed by the control, it calculates the ramp required
to move the process from the starting value (current PV) to the desired
value (programmed SP) in the time allowed.
Care must be taken, however, that the process does actually reach the
soak value before the soak time starts. Make sure to test any program for
desired results before running production material.
Do not operate Self Tune while a ramp function is operating. The
ramp function will prevent the Self Tune from operating properly.
Make sure that all tuning is set up before operating Ramp / Soak.
Program Setup
The programming for the Ramp / Soak function is done in the Secondary
Menu.
In the Secondary Menu INDEX to Prog and make sure that Prog is set to
OFF.
Skip the StAt setting (this is discussed later) and press INDEX to 1rt.
Set 1rt to the amount of time you want for the ramp. This value is in time
units from 00.01 to 99.59 (hh,mm). Press INDEX.
Set 1St to the amount of time you want for the soak. This value is in time
units from 00.01 to 99.59 (hh,mm). Press INDEX.
The last menu item for the ramp / soak function is PEnd. PEnd determines
what the control does when the program has ended. You may choose to
Hold the set point (SP1), or turn the outputs off (OoFF).