DMX-CAN Manual
page 37
rev 1.6
0 – Sync output feature is off
1 – Waiting for sync condition
2 – Sync condition occurred
StepNLoop Closed Loop Control
DMX-CAN features a closed-loop position verification algorithm called StepNLoop
(SNL). The algorithm requires the use of an incremental encoder.
SNL performs the following operations:
1)
Position Verification: At the end of any targeted move, SNL will perform a
correction if the current error is greater than the tolerance value.
2)
Delta Monitoring: The delta value is the difference between the actual and the
target position. When delta exceeds the error range value, the motor is
stopped and the SNL Status goes into an error state. Delta monitoring is
performed during moves – including homing and jogging. To read the delta
value, use the
DX
command.
See Table 7.5 for a list of the SNL control parameters.
SNL Parameter
Description
Command
Tolerance
Maximum error between target and actual position that
is considered “In Position”. In this case, no correction
is performed. Units are in encoder counts.
SLT
Error Range
Maximum error between target and actual position that
is not considered a serious error. If the error exceeds
this value, the motor will stop immediately and go into
an error state.
SLE
Correction Attempt
Maximum number of correction tries that the
controller will attempt before stopping and going into
an error state.
SLA
Idle Tolerance
After correction, if the remaining error is greater than
this value, an additional correction will be performed
using idle current instead of run current.
SLM
Table 7.5
To enable/disable the SNL feature use the
SL
command. To read the SNL status, use
SLS
command to read the status.
See Table 7.6 for a list of the
SLS
return values.
Return
Value
Description
0
Idle
