Newport New Focus Picomotor 8743-CL, User Manual

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88
DB
Description
Deadband set.
Syntax
xx DB nn
Remarks
This command is used to set the position deadband value for an axis. Since a majority of
electro-mechanical systems have mechanical backlash or frictional hysteresis, closed-loop
positioning can at times lead to oscillation or limit cycling of the systems around a desired
position. In such situations, setting position deadband value judiciously can avoid limit cycling
of the systems.
Note that this command is effective only during position regulation (holding position) as
opposed to while moving. Also, the positioning units must be in ‘Counts’ (see SN command)
and closed-loop positioning must be enabled (see MM command) for DB command to take
effect.
NOTE: An error will be generated if the controller makes more than 100 consecutive
unsuccessful attempts to correct the stage position, but is unable to bring the
following error to within specified deadband setting.
Argument Value Description
xx
1 to 2 Axis number
nn
0 to 2147483647 Deadband value (units). Default = 0
Example
2DB0 (set deadband value to 0 encoder counts)
2SN1 (set units to encoder counts)
2FE1000 (set following error threshold to 1000 counts)
2CL0.1 (set closed-loop update interval to 0.1 second)
SM (save settings to non-volatile memory)
2MM1 (enable closed-loop positioning)
2PA+100 (move to encoder count po100)
See Also
DB?, SN, MM, FE, CL