Analog Inputs - Allen-Bradley PowerFlex 70 Reference Manual

Analog Inputs

Analog Inputs
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While the process is normal and running from the analog input, everything
proceeds normally. However, if the wire for the analog input should be severed or
the sensor malfunction so that the 4-20mA signal is lost, the following sequence
occurs:
1. The drive will sense the signal loss.
2. An active Type 1 Alarm is created and the last signal value is maintained as the
speed reference.
3. The alarm activates the digital output relay to light the alarm light for the
operator.
4. The operator uses the HIM to switch the drive to Manual Control (see Auto/
Manual).
5. The operator manually brings the process to a controlled stop until the signal
loss is repaired.
Alarm Queue (PowerFlex 700 Only)
A queue of 8 parameters exists that capture the drive alarms as they occur. A
sequential record of the alarm occurrences allows the user to view the history of
the eight most recent events.
262 [Alarm 1 Code]
263 [Alarm 2 Code]
264 [Alarm 3 Code]
265 [Alarm 4 Code]
266 [Alarm 5 Code]
267 [Alarm 6 Code]
268 [Alarm 7 Code]
269 [Alarm 8 Code]
A code that represents a drive alarm. The codes will
appear in the order they occur (first 4 alarms in – first 4
out alarm queue). A time stamp is not available with
alarms.
Possible Uses of Analog Inputs
The analog inputs provide data that can be used for the following purposes:
• Provide a value to [Speed Ref A] or [Speed Ref B].
• Provide a trim signal to [Speed Ref A] or [Speed Ref B].
• Provide a reference when the terminal block has assumed manual control of
the reference
• Provide the reference and feedback for the PI loop. See
page 135.
• Provide an external and adjustable value for the current limit and DC braking
level
• Enter and exit sleep mode.
•
Provide a value to [Torque Ref A] or [Torque Ref B].
FV
Vector
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
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Process PI Loop on
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