6
temperature value continues to increase or decrease, case of diagnostic 5 occurs
160
20
4
3.5
21.5
FOU = OFF
FOU = On
20.5
3.8
I [mA]
-25
0
150
MEW
MAW
ASP
AEP
T [°C]
1
2
Figure 1: Output characteristics analogue output with factory setting
1
Setting [OU2] = I
2
Setting [OU2] = Ineg
MAW = initial value of the measuring range, MEW = final value of the measuring range,
ASP = analogue start point, AEP = analogue end point
5.2 Diagnostic function
By measuring with two different, thermically coupled sensor elements (NTC, PT
1000) the unit automatically detects drifts and errors during temperature measure-
ment�
A mean average value is formed from the measured individual NTC and Pt 1000
values� This mean value is the basis for the provided measured temperature value
and also the basis for the diagnostic messages with the drift monitoring
�
Besides temperature drift other errors can be detected
es)� Via the parameter drEd you set which of the diagnostic cases is signalled (
)�
The message of diagnostic cases is given by an analogue signal in 2-wire opera-
tion, in addition by a switching signal in 3-wire operation�
