Azbil DCP31 - Page 170

7-60
Chapter 7. PARAMETER SETUP
(5) Example: Using Azbil Corporation’s PGM ** 2A1 series
V
SSR
: 3 to 6V
Z : 260Ω ± 5%
V
D
: 0.8 to 1.3V
•WhatvalueshouldIObesettowhenconnectingonePGM?
 Asshowninthefigureontheright,afixed-currentsystemisused
forthevoltageoutputofthiscontroller.Thefixedcurrentcanbe
calculatedasfollowsfromtheinputvoltagerangeofPGM:
8.9mA ≤ 1 ≤ 17.2mA
I
MIN
× Z
MIN
+ V
D/MIN
> 3
I
MIN
> 8.9mA
I
MAX
× Z
MAX
+ V
D/MAX
< 6
I
MAX
< 17.2mA
•HowmanyPGMscanbeconnected?
 Acurrentof8.9mAormoremustflowtoasinglePGM.Onthe
otherhand,themaximumcurrentofthecontrolleris22.0mA.
Accordingly,twoPGMscanbeconnectedinparallel.
Inthecaseofaseriesconnection,duetothemaximumoutput
current(22.0mA)andallowableloadresistance(600Ω),the
maximumvoltagethatcanbeappliedtoaloadbecomes13.2V
(22.0mA × 600Ω).
Whenacurrentof8.9mAflowstoaPGM,themaximumvoltage
atbothofitsinputterminalsbecomes3.7V.
0.0089 × 260 × 1.05 + 1.3 = 3.7V
 Accordingly,13.2÷3.7=3.56,whichmeansthatthreePGMscan
beconnectedinseries.
Theabovecalculationassumesoperationintheworstconditions.
Forexample,eveniffourPGMsareconnectedinseries,they
shouldoperatenormallyifavoltageof3Vormoreisappliedto
eachofthePGMsinavoltageONstate.

C 9 0
(Special functions)
•Normallysetto0.
•Inthecaseofsetup102,currentoutput(includingheat-coolout-
put)0to100%forthecontroloutputbecomes0to20mA.Note,
however,thatat0%orless,thecurrentis0mA.
 Atoutput1mAorless,accuracyis±0.5%.
•Inthecaseofsetup103,currentoutput(includingheat-cool
output)andauxiliaryoutput0to100%forthecontroloutput
becomes0to20mA.Note,however,thatat0%orless,thecurrent
is 0mA.
Atoutput1mAorless,accuracyis±0.5%.
•Whensetto104,theratetime(d,dd)andresettime(I,dI)settings
areinunitsof0.1s.
•Whensetto105,theratetime(d,dd)andresettime(I,dI)settings
areinunitsof0.01s.
Z
I
PGM ** 2A1DCP31
V
D