Can I determine the display (resolution) of the measured values myself?

No, that does not work! The resolution depends on the set current and voltage transformers and is therefore independent of the actual measured variable.

Here is an overview:

• Voltage display of primary phase-to-phase voltage
  

primary phase-to-phase voltage		display	dimension via interface
> 60 kV	…750 kV	xxx.x kV	dim. U =	2
> 6 kV	…60 kV	xx.xx kV	dim. U =	1
700 V	…6 kV	xxxx V	dim. U =	0
100 V	…600 V	xxx.x V	dim. U =	-1

• Current display depending on primary current
  

primary current		display	dimension via interface
> 60 kA	…150 kA	xxx.x kA	dim. I =	2
> 6 kA	…60 kA	xx.xx kA	dim. I =	1
> 600 A	…6 kA	xxxx A	dim. I =	0
65 A	…600 A	xxx.x A	dim. I =	-1
10 A	…60 A	xx.xx A	dim. I =	-2
1 A	…5 A	x.xxx A	dim. I =	-3

• Power and energy display depending on the product of
• primary phase voltage and primary current
  

primary current		display	dimension via interface
> 36 GW	…112.5 GW	xxx.x MkW	dim. P =	8
> 3.6 GW	…36 GW	xx.xx MkW	dim. P =	7
> 360 MW	…3.6 GW	xxxx MW	dim. P =	6
> 36 MW	…360 MW	xxx.x MW	dim. P =	5
> 3.6 MW	…36 MW	xx.xx MW	dim. P =	4
> 360 kW	…3.6 MW	xxxx kW	dim. P =	3
> 36 kW	…360 kW	xxx.x kW	dim. P =	2
> 3.6 kW	…36 kW	xx.xx kW	dim. P =	1
400 W	…3.6 kW	xxxx W	dim. P =	0
100 W	…300 W	xxx.x W	dim. P =	-1