SBC PCD2 Series - Page 207

Saia-Burgess Controls AG
Manual I/O-modules for PCD1 │ PCD2 series │ Document 27-600 – Release ENG09 │ 2019-05-01
6-64
I/O modules PCD3
PCD3.W2x0
6
Temperature measurement with Pt1000
Inthetemperaturerange– 50°to+400°C,thefollowingformulaecanbeusedfor
working to an accuracy of ± 1 % (± 1.5°C).
Repeatingaccuracyissignicantlyhigher.
T[°C]=
– 261.8
DV
2.08 – (0.509 • 10
-
³ • DV)
T=temperature in °C DV = digital value (0…1023)
Example 1: digital value DV = 562
temperature T in °C ?
T[°C]=
– 261,8
562
2.08 – (0.509 • 10
-
³ • 562)
= 51.5°C
DV =
2.08 • (261.8 + T)
1 + (0.509 • 10
-
³ • (261.8 + T))
DV=digital value (0…1023) T = temperature in °C
Example 2: preset temperature T= –10°C
corresponding digital value DV ?
DV =
2.08 • (261.8 - 10)
1 + (0.509 • 10
-
³ • (261.8 - 10))
= 464
Resistance measurement up to 2.5 kΩ
Specialtemperaturesensorsoranyotherresistancesupto2.5kΩcanbecon-
nected to the PCD3.W220. The digital value can be calculated as follows:
DV =
4092 • R
(7500 + R)
where0≤DV≤1023andR=theresistancetobemeasuredinΩ.