Data Sheet

13
Note
It is not possible to measure resistance sensors through Analog inputs in Group 1. Such measurement
is possible to achieve trough connection to Group 1 analog outputs. This fact is further described in
chapter 2.4.7.
Measuring of voltage and current on analog input of group 1
For precise measurement of analog input, it is necessary to do a correction of converted value with
reference voltage stored of the processor and also a correction of other coefficients read directly from
corresponding registers. For doing so there is a following formula of voltage calculation.





 





  





 








[V]
Current can be calculated in a similar way using the following formula.





 









  

 








[mA]
2.4.7 Analogue output connection
Analog outputs serve for regulation of external devices (such as three-way valves or heat exchangers)
by output analogue signal in range of either 0-10 V or 0-20mA.
External device is to be connected to screw connectors of AOY.X and AOGND. The following illustration
demonstrates connection of external device to analog output.
Note
Analog output in the Group 1 features the possibility of measuring resistor sensors (e.g. Pt1000).
The following formula can be used to set the proper value of AO when set as voltage output.













 








 




 
Were the V
AO1
desired
is the desired value in Volts.
Alternatively, the following formula can be used for current output.