Yaskawa P7B Drive Bypass - Manual (Page 162)

Programming 5 - 68
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L4 Speed Command Loss Detection
" L4-05 Frequency Reference Loss Detection Selection
" L4-06 Frequency Reference at Loss of Frequency Reference
Setting Range: 0.0 to 100.0% of previous speed command
Factory Default: 80.0% of previous speed command
The Drive can be configured to compensate for the loss of its external speed command. An external speed command is
considered lost if it drops 90% of its value in 400mS or less.
Fig 5.34 Loss of Frequency Reference Timing Diagram
To enable Frequency loss detection, set L4-05= “1: Enabled @ % of PrevRef”. If Frequency Reference Loss Detection is
enabled and the reference is lost, the Drive continues to operate at the speed commanded by parameter L4-06. When the speed
command returns, the Drive again follows the speed command.
Setting H2-01/H2-02= “C: Loss of Ref”, configures a digital output as a Frequency Reference Loss indication only when
L4-05= “1: Enabled @ % of PrevRef”.
Setting Description
0 Disabled (factory default)
1 Enabled @ % of PrevRef
t
Frequency
Reference
Output
Frequency
t
10%
T
L4-06
100%
T = 400mS
100%
10%
TIME