YASKAWA F7 Programming Manual page 99

The frequency reference is considered lost when the voltage level drops 90% in 0.4 seconds. Parameter L4-05 determines the
Drive's reaction to a loss of reference state in addition to turning on the Loss of Reference digital output.
The Loss of Reference digital output will only initiate if the Drive is configured for the frequency reference to be via one of
the analog inputs (A1, A2, or A3).
100%
80%
Analog
Speed Command
10%
T
T = 400ms
Loss of
ON (Closed)
Reference
Output
OFF (Open)
t
TIME
Fig. 60 Loss of Reference Function Characteristics
Function: DB Overheat
Setting: D
When the dynamic braking resistor (DB) overheats or the braking transistor is in a fault condition, the DB Overheat
configured digital output will close.
Function: Fault
Setting: E
The Fault configured digital output will close whenever the Drive experiences a major fault with the exception of the CPF00
and CPF01 (Digital Operator Communications Faults).
Function: Not Used
Setting: F
The Not Used setting can be used to disable the digital output.
Function: Minor Fault
Setting: 10
A Minor Fault, also referred to as an alarm, indicates that a condition exists that may be critical to the Drive or application but
does not require the Drive to stop. A minor fault will be flashed on the digital operator but neither the Fault output (MA-MB)
nor any digital output configured as a Fault output (H2-0x= E) will close. Any digital output configured as Minor Fault will
close whenever a minor fault of alarm condition exists.
Function: Reset Command Active
Setting: 11
A Reset Command Active digital output will close to signal that a fault reset is being attempted from terminals, serial
communication, or communication option board.
Programming 91