Installation guide

Keyword Reference Guide
MN1270 02.2002 135
Auxiliary encoder channel Value to write to VELENCODER
0 (NextMove BX and NextMove PCI) -1
1 (NextMove PCI with expansion card) -2
To turn off dual encoder feedback, the velocity encoder must be set to the same encoder as is being
used for position feedback. This can be achieved by reading the
AXISCHANNEL keyword.
For example, turn off dual encoder feedback on axis 0.
VELENCODER.0 = AXISCHANNEL.0
Example 1
On NextMove PCI, axis 2 controls a table through a leadscrew. There are two encoders available, one
attached to the table and another to the motor shaft. Axes 0, 1 and 3 are also in use. To set this system
up for dual encoder feedback, the position feedback encoder (on the table) should be attached to
encoder input 2. The velocity encoder (on the motor) should be attached to the auxiliary encoder input.
The
VELENCODER keyword is used to specify the location of the velocity feedback.
VELENCODER.2 = -1
Example 2
On NextMove BX, axis 0 provides position feedback and axis 1 provides velocity feedback. The
VELENCODER keyword used to specify that axis 0 is using dual encoder feedback.
VELENCODER.0 = 1
See also:
AXISCHANNEL, CONFIG
VELFATAL/VLF
Purpose:
Set a threshold for the maximum difference between demand and actual velocity.
Controllers Supported:
NextMove PCI NextMove PC NextMove BX MintDrive ServoNode 51
Format:
VELFATAL [axes] = <expression> {,<expression> ...}
v = VELFATAL[axis]
Dot Parameters:
Axis – Axis No.
Attributes:
Controller Read Write Command Multi-
Axis
Scaled Default Range
NextMove
8388607.0
0.0 < x 8388607.0
Description:
Velocity error checking allows the measured velocity of an axis to be compared to its demand velocity.
If the difference between the two values exceeds the limit set with
VELFATAL, then an error will be
created. This allows for a burst of noise or poor drive performance to be detected.
If the velocity error exceeds the fatal value, an asynchronous error will be generated and bit 17 of
AXISERROR will be set. The response to this error is controlled with the function VELFATALMODE.
See Also:
AXISERROR, VELFATALMODE