User manual

URDR0001 - User manual - 27
Parameters to congure for the Cooling P.I.D. are the following (ex: action asso-
ciated to alarm 1):
A L .1 = cooL Alarm 1 selection (Cooling);
P. b . M . : Proportional band multiplier;
ou.d.b. : Overlapping / Dead band;
co.t.c. : Cooling time cycle.
Parameter
p.b.m. (that ranges from 1.00 to 5.00) determines the proportional
band of cooling basing on the formula:
Cooling proportional band =
P. b . x P. b . M .
This gives a proportional band for cooling which will be the same as heating
band if
P. b . M . = 1.00, or 5 times greater if P. b . M . = 5.00.
Integral and derivative time are the same for both actions.
Parameter
ou.d.b. determines the percentage overlapping between the two
actions. For systems in which the heating and cooling output must never be
simultaneously active a dead band (
ou.d.b. ≤ 0) can be congured, and vice
versa an overlapping (
ou.d.b. > 0).
The following gure shows an example of dual action P.I.D. (heating-cooling)
with
t.i . = 0 and t.d. = 0.
ACTIVE
ACTIVE
SPV
PV
p. b x p.b.m. (COOL)
au.d.b. < 0
p. b (HEAT)
COMMAND OUTPUT (HEAT)
ALARM OUTPUT (COOL)