Keysight U1252B - Charge Terminal Alert; Figure 2-17 Charge Terminal Alert

Making Measurements 2
Keysight U1251B and U1252B User’s and Service Guide 75
Charge terminal alert
The meter sounds an alert beep when the terminal detects a voltage level
of more than 5 V and the rotary switch is not set to the corresponding
location. The primary display indicates a flashing “Ch.Err” until the lead is
removed from the input terminal. Refer to Figure 2-17 below.
Figure 2-17 Charge terminal alert