BackwardMotionCancellationMode

Operational mode of the Backward Motion Cancellation circuit

Applicable product(s): 1624 Grablink Base, 1623 Grablink DualBase, 1622 Grablink Full, 1626 Grablink Full XR.

Parameter Info

Class Category Level Type Access
Channel Encoder Control ADJUST Enumerated Set and Get
Num ID String Identifier C, C++ identifier
10352 << 14 BackwardMotionCancellationMode MC_BackwardMotionCancellationMode

Parameter Description

The backward cancellation circuit stops sending line trigger pulses as soon as a backward motion is detected. If such an event occurs, the acquisition is stopped.

When the backward cancellation control is configured in the FILTER mode (F-mode), the line acquisition resumes as soon as the motion is again in the forward direction. Therefore, the cancellation circuit filters out all the pulses corresponding to the backward direction.

When the backward cancellation control is configured in the COMPENSATE mode (C-mode), the line acquisition resumes when the motion is again in the forward direction at the place it was interrupted. Therefore, the cancellation circuit filters out not only the pulses corresponding to the backward direction, but a number of forward pulses equal to the number of skipped backward pulses.

In C-Mode, the cancellation circuit uses a "backward pulse counter" that:

  • Increments by 1 every clock in the backward direction
  • Decrements by 1 every clock in the forward direction until it reaches 0
  • Resets at the beginning of each MultiCam acquisition sequence, more precisely, at the first trigger event of the sequence. This trigger is considered as the reference for the position along the web for the whole acquisition sequence.

In C-Mode, all pulses occurring when the counter value is different of zero are blocked.

The counter has a 16-bit span; backward displacement up to 65535 pulses can be compensated.

Parameter Usage

Relevance condition(s):
  • Condition: The line trigger originates from a quadrature motion encoder.
  • Condition: The rate converter circuit is unused.

Parameter Values

Enumeration: OFF, FILTERED, COMPENSATE

Table 1. OFF
MC_BackwardMotionCancellationMode_OFF

Applicable product(s): 1624 Grablink Base, 1623 Grablink DualBase, 1622 Grablink Full, 1626 Grablink Full XR.

Description

The backward motion cancellation circuit is disabled.

Default value.

Table 2. FILTERED
MC_BackwardMotionCancellationMode_FILTERED

Applicable product(s): 1624 Grablink Base, 1623 Grablink DualBase, 1622 Grablink Full, 1626 Grablink Full XR.

Description

The backward motion cancellation circuit is enabled and configured for the filter mode.
Applicability condition(s):
  • Condition: LineRateMode is set to PULSE
  • Condition: LineTrigCtl is set to DIFF2
Table 3. COMPENSATE
MC_BackwardMotionCancellationMode_COMPENSATE

Applicable product(s): 1624 Grablink Base, 1623 Grablink DualBase, 1622 Grablink Full, 1626 Grablink Full XR.

Description

The backward motion cancellation circuit is enabled and configured for the compensation mode.
Applicability condition(s):
  • Condition: LineRateMode is set to PULSE
  • Condition: LineTrigCtl is set to DIFF2