Chapter 3 – Configuration
35
aggressive accelerations are possible during which the motor may skip poles (lose
position). This loss of position can be less than 50 milliseconds; if so, it will not be
recognized as a stall.
Because the command velocity must be in the 3 – 37 rps range for stall detect to be
active, the drive will not recognize static loss of position as a stall. Therefore, do
not use this function to detect loss of holding torque in vertical applications.
Settings are summarized below.
Stall Detect Settings:
Command:
DSTALL
Default:
Disabled (DSTALL0)
Velocity Range:
3 to 37 rps
Contributing Parameter: LJRAT
Stall detect performance is based on motor parameters that you set up with Motion
Planner. For optimum performance, accurate motor parameters are required.
If you select a Compumotor motor with Motion Planner, the motor parameters are
set automatically, according to the motor you have chosen. If you use other
motors, see
Appendix B – Using Non-Compumotor Motors
.
Use the following procedures to configure the stall detect settings.
Configuring Stall Detect
The DSTALL command sets the sensitivity for the stall detection circuitry. The default
setting is
disabled. (DSTALL0)
NOTE: Match the motor to the load (see the procedure on the following pages)
before
you configure stall detect settings.
1.
Enter an accurate value for LJRAT.
The LJRAT command sets the system’s load-to-rotor inertia ratio. LJRAT must be
set accurately in order for stall detect to function properly.
2.
Begin configuration with low DSTALL values.
•
1 - 50 is the full range
•
0 is
off
The table below lists effective ranges of DSTALL values. Enter a value, based on
your motor size:
Motor Frame Size:
Size 23
Size 34
Size 42
DSTALL Value Range:
1 – 15
10 – 40
30 – 50
3.
Verify the DSTALL value you entered by forcing a stall as you monitor TASX. At the
precise moment the stall occurs, TASX Bit #17 should be set. If Bit #17 is set before
or after the stall occurs, modify the DSTALL value as follows:
•
If Bit #17 is set
before the stall occurs, decrease the DSTALL value
•
If Bit #17 is set
after the stall occurs, increase the DSTALL value
4.
Run the system for an extended period of time to verify that no false stalls are
detected.
Configuring Fault on Stall Mode
1.
If you enable the Fault on Stall mode (ESK1), the occurrence of a stall will immedi-
ately stop pulses from being sent to the motor and will disable the drive (DRIVE0)
2.
If Fault on Stall is enabled (ESK1), the stall is reported by the following commands:
•
TASX
bit #17
•
TER
bit #1
