SBC PCD2.M5 Series - Page 165

Hardware Manual for the PCD2.M5 Series│Document 26/856; Version EN 12│2014-07-24
Saia-Burgess Controls AG
Analogue input modules
Input/output (I/O) modules
6-54
6
Temperature measurement with Pt 1000
In the temperature range -50 °C to +200 °C, the following formulae can be used for
working to an accuracy of ± 1 %(±1.5 °C).Repeatingaccuracyissignicantlyhigher.
T = temperature in ° C   DV=digitalvalue(0 … 1023)
Example 1: digital value DV = 562
temperature T in °C?
DV=digitalvalue(0 … 1023)  T=temperaturein° C
Example 2: preset temperature T= –10°C
corresponding digital value DV?
Resistance measurement up to 2.5 kΩ
Specialtemperaturesensorsoranyotherresistancesupto2.5kΩcanbeconnected
to the PCD2.W220. The digital value can be calculated as follows:
where0≤DV≤1023andR=theresistancetobemeasuredinΩ.
T[° C]=
- 261.8
DV
2.08-(0.509•10
-
³•DV)
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 =
2.08•(261.8-10)
1+(0.509•10
-
³•(261.8-10))
= 464
DV =
4092 • R
(7500+R)