Operations introduction 
  Copyright © Itech Electronic Co., Ltd.  52 
>Protect>Alimit set ON, Apoint set OCP current value, Adelay set delay 
time before alarm. When the software OCP function is active, if the load 
current  value  is  over  the  over  current  protection  set  value,  load  will 
automatically off, VFD displays OCP. At the same time, the OC and PS bits 
in the status register will be set and they will remain until they are reset. 
Operations to clear the OCP state: 
Check  whether  the  input  current  is  within  the  load’s  rated  current  or  the 
programmed  protecting  current  ranges,  if  it  is  outside  the  range,  please 
disconnect the instrument under test. Press any key on the front panel (or send 
commandPROTection:CLEar),  the  (OVP)  displayed  on  the  front  panel  will 
disappear, load exits OCP protection state. 
4.11.3 Over power protection (OPP) 
The electronic load includes both hardware and software OPP features. 
⚫  Hardware OPP: the electronic load allows user to set a power protection 
limit in hardware which will limit the power in the range you set when the 
OPP  condition  occur.  Hardware  OPP  will  not  change  the  load ON/OFF 
state.   
⚫  Software  OPP:  users  can  set  load’s  software  OPP  value,  steps: 
Shift+5>Protect>Point set OPP power value, Plimit set alarm delay. If the 
load power value is OPP delay time, load will automatically turned off, VFD 
will display OPP. At the same time, the OP and PS bits in the status register 
will be set and they will remain until they are reset. 
Operations to clear the OPP state: 
Check whether the input power is in the rated power range or the programmed 
protecting ranges. If it is outside the range, please disconnect the instrument 
under  test.  Press  any  key  on  the  front  panel  (or  send 
commandPROTection:CLEar),  the  (OPP)  displayed  on  the  front  panel  will 
disappear, load exits OPP protection state. 
4.11.4 Over temperature protection (OTP) 
When  load’s  internal  circuit  temperature  is  over  85℃, load will enable OTP. 
Input will automatically turned off, VFD display OTP. At the same time the OT 
and PS bits in the status register will be set, they will remain until they are reset. 
Operations to clear the OTP state: 
when load temperature dropped to the protecting point, press any key on the 
front panel(or send command PROTection:CLEar), the (OTP) displayed on the 
front panel will disappear, load exits OTP protection state. 
4.11.5 Reverse voltage alarm (LRV) 
Once in reverse connection condition, main frame screen displays LRV, and 
they will remain until the reverse connection is eliminated. 
Operations to clear the reverse voltage state: 
Check whether the connection is reversed. If so, disconnect the object to be 
measured. 
4.12 Save and recall operation 
The  stored  setting  of  all  channels  can  be  recalled,  the  stored  parameters 
includes working mode, voltage/ current value, slew rate, transient setting and 
so on. It can save up to 101 groups of setting parameters. The 0
th
 group can be 
used as boot parameters. The 1
st
 to 100
th
 groups can be used as automatic