Arcus DMX-ETH, Руководство пользователя

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DMX ETH Manual page 39 rev 1.16
Latch Input
The DMX-ETH module provides a high speed position latch input.
This input performs high speed position capture of both pulse and encoder positions but
does not reset the pulse or encoder position counters.
Note:
When StepNLoop mode is enabled, the position value should be ignored.
Use the
LT command to enable and disable latch feature. To read the latch status, use
LTS
command.
Following are return value description for
LTS command.
Return Value Description
0 Latch off
1 Latch on and waiting for latch trigger
2 Latch triggered
Table 7.4
Once the latch is triggered, the triggered position can be retrieved using LTP (latched
pulse position) and LTE (latched encoder position) commands.
StepNLoop Closed Loop Control
DMX-ETH 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
StepNLoop Ratio
†Ratio between motor pulses and encoder counts.
This ratio will depend on the motor type, micro-
stepping, encoder resolution and decoding multiplier.
Value must be in the range [0.001 , 999.999].
SLR
Tolerance
Maximum error between target and actual position that
is considered “In Position”. In this case, no correction
SLT