Function and Features 
  Copyright © ITECH Electronic Co., Ltd.  29 
status. 
NOTE 
Please confirm whether it is necessary to set loading voltage, a step that provides 
convenience for limiting working voltage value. If not necessary, do not set the 
loading voltage without authorization to prevent unnecessary trouble from failure of 
loading. 
If the instrument cannot load, please firstly check whether the VON function is set. If 
yes, reset the Von value to minimum value (which may be directly set as 0. If 
minimum voltage value of instrument is not 0, press 0 for confirmation and the menu 
will automatically set the value as minimum value). 
This function is invalid under CV mode. 
When VON LATCH function is started, the load starts load test only when the 
power voltage rises and is higher than Von Point loading voltage. When the 
power voltage drops and is lower than Von Point unloading voltage, the load will 
not unload. 
 
Load working range when VON LATCH is started 
 
3.17 Protective function 
The load is provided with following protective functions: overvoltage protection 
(OVP), overcurrent protection (OCP), overpower protection (OPP) and 
overtemperature protection (OTP). 
If any one of the above protections is enabled, the load will have corresponding 
actions. Press any key on the front board to reset protection functions. For 
example, in case of overtemperature protection, the load will give alarm and the 
input will automatically switch to OFF status. The load VFD will display OTP. 
3.17.1 Overvoltage protection (OVP) 
The load will be immediately OFF and the buzzer will sound if the overvoltage 
circuit is triggered. OV and VF bits of the status register will be set and OVP will 
be displayed on the screen of the load till resetting. In case of overvoltage 
protection, the VF pin of the 8-pin connector on rear board of the load outputs 
TTL high level and the VF pin can be used for controlling output status of the 
power to be tested.