What is the setting accuracy of the voltage monitor (VMON) in PWR-01 series?

The setting accuracy is 2.5 % of full scale (f.s.) as follows:
0 to 5 V range: 0.125 V
0 to 10 V range: 0.25 V
For the details, read the user’s manual – chapter of Specifications – Common Specifications – Signal output and input.