PSU Series Programming Manual 
166 
Error Messages & Messages 
The following error messages or messages may appear on the PSU 
screen during operation.  
 
Master & slave board over temperature protection in 
PSU 
Master board over temperature protection  in PSU 
Slave board over temperature protection in PSU 
Hardware over voltage protection 
USB mass storage is not present 
No (such)file in USB mass storage 
Slave occurs Off-line (Multi-drop mode) 
 
External control of output. Output off (F-94=0, 
High=on) 
External control of output. Output off (F-94=1, 
Low=on) 
 
Communication 
Interface Messages 
Rear USB port connected to PC 
Rear USB port disconnected from PC 
Mass storage plugged into front USB port 
Mass storage removed from front USB port