Dwyer 8600 - Manual (Page 12)

949-1277-3 Page 12 December, 1998
Thus, the operator only needs to program the target set point and the time
desired to reach 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.
Soaks (or dwells) are ramp segments where the target set point is the same
as the beginning process value. This allows for multistage ramps without
wasting intermediate soak steps. Care must be taken, however, that the
process does actually reach the soak value before the soak time starts. If
not, the next segment will calculate a slope from the starting PV to the target
SP. Depending on your process requirements, this difference may be
important. 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
All of the programming for the Ramp / Soak function is done in the
Secondary Menu. You may wish to work out your program on paper before
going into the programmer menu sequence.
In the Secondary Menu INDEX to Prog and make sure that Prog is set to
OFF.
INDEX to PSEt and turn On.
Skip the StAt setting (this is discussed later) and press INDEX to 1ti.
The following items repeat in the following order: 1ti, 1SP, 1A1 (if alarm 1
is programmed as an event), 1A2 (if alarm 2 is programmed as an event),
2ti, 2SP, 2A1, 2A2, . . . , 16ti, 16SP, 16A1, 16A2. To avoid repetition each
item will only be described once.
Set 1ti to the amount of time you want for the first ramp. This value is in
time units (determined by the tbAS menu item) from 0 to 9999. Press
INDEX
Set 1SP to the target value desired for the first ramp. This value is in actual
units just like SP1. If the control is programmed for temperature, then the
SP displays are in temperature. If the control is programmed for some other
engineering unit, the SP is set in that unit.