AB F121 fault code meaning
AB / F121
Series: PowerFlex 700H
I/O Comm Loss
AC drive
Meaning: An I/O Board lost communications with the Main Control board.
Possible causes
Source:
Series: PowerFlex 700L(700S second-generation control)
700L Latch Err2
AC drive
Meaning: Fault reporting failure on secondary 700L power structure.
Possible causes
Source: Allen-Bradley PowerFlex 700L Liquid-Cooled Drive User Manual 20L-UM001 Table 6.B/6.C