YASKAWA T1000V Technical Manual page 126

5.2 b: Application
b5-11: PID Output Reverse Selection
■
Determines whether a negative PID output reverses the drive operation direction or not. When the PID function is used to
trim the frequency reference (b5-01 = 3 or 4), this parameter has no effect and the PID output will not be limited (same as
b5-11 = 1).
No.
b5-11
Setting 0: Reverse Disabled
Negative PID output will be limited to 0 and the drive output will be stopped.
Setting 1: Reverse Enabled
Negative PID output will cause the drive to run in the opposite direction.
PID Feedback Loss Detection
■
The PID Feedback Loss Detection function can detect broken sensors or broken sensor wiring. It should be used
whenever PID control is enabled to prevent critical machine conditions (e.g. acceleration to max. frequency) caused by a
feedback loss.
Feedback loss can be detected in two ways:
• Feedback Low Detection:
Detected when the feedback falls below a certain level for longer than the specified time.
• Feedback High Detection:
Detected when the feedback rises beyond a certain level for longer than the specified time.
The following figure explains the working principle of feedback loss detection when the feedback signal is too low.
Feedback high detection works in the same way.
Figure 5.19
The parameters necessary to set up the feedback loss detection are explained below.
b5-12: PID Feedback Loss Detection Selection
■
Enables or disables the feedback loss detection and sets the operation when a feedback loss is detected.
No.
b5-12
Setting 0: Digital Output Only
A digital output set for "PID feedback low" (H2-
detection level set to b5-13 for the time set to b5-14 or longer. A digital output set for "PID feedback high" (H2-
3F) will be triggered if the PID feedback value is beyond the detection level set to b5-36 for the time set to b5-37 or
longer. Neither a fault nor an alarm is displayed on the digital operator. The drive will continue operation. When the
feedback value leaves the loss detection range, the output is reset.
126
Parameter Name
PID Output Reverse Selection
PID feedback value
PID
Feedback
Detection
Loss Level
(b5-13)
PID Feedback
Low Detection Time
(b5-14)
Figure 5.19 PID Feedback Loss Detection
Parameter Name
PID Feedback Loss Detection Selection
no FbL
detection
PID Feedback
Low Detection Time
(b5-14)
= 3E) will be triggered if the PID feedback value is below the
YASKAWA ELECTRIC SIEP C710606 44B YASKAWA AC Drive T1000V Technical Manual
Setting Range
0 or 1
time
FbL detection
Setting Range
0 to 5
Default
0
Default
0
=