109
736
Write or read error occurred
Description A warning message is shown on the display.
Remedy Check the USB stick and the files on the USB stick or replace 
the USB stick.
Remove the USB stick only when the ‘Data Transfer’ LED is no 
longer flashing or lit.
If status code persists: Contact a Fronius-trained service tech-
nician
737
File could not be opened
Description A warning message is shown on the display.
Remedy Error is corrected automatically. If necessary, remove and rein-
sert the USB stick.
If status code persists: Contact a Fronius-trained service tech-
nician
738
Log file could not be saved (e.g., USB stick is write-protected or full)
Description A warning message is shown on the display.
Remedy Free up memory. Remove write-protection. If necessary, check 
or replace the USB stick.
If status code persists: Contact a Fronius-trained service tech-
nician
739
Initialization error (e.g., USB stick is write-protected, full, or faulty)
Description A warning message is shown on the display.
Remedy Free up memory. Remove write-protection. If necessary, check 
or replace the USB stick.
If status code persists: Contact a Fronius-trained service tech-
nician
740
Initialization error - error in USB stick file system
Description A warning message is shown on the display.
Remedy Check USB stick, or reformat it on a PC to FAT12, FAT16 or 
FAT32.
If status code persists: Contact a Fronius-trained service tech-
nician
741
Error when recording logging data
Description A warning message is shown on the display.