Aerotech UNIDEX 600 Series, User Manual

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Parameters U600 User’s Guide
C-16
Aerotech, Inc.
Version 1.4
C.2.26. DACOFFSET
The DACOFFSET axis parameter is used to null any offset in the command to the drive,
typically used only for axes in the velocity mode (tachometer based systems). Brushless
motors utilize the PHASEAOFFSET and PHASEBOFFSET axis parameters.
The value is entered as a signed number representing the number of D/A counts (+/-)
required to bring the DAC output command to zero volts. This value is added to all motor
command values before being output to the DAC.
For example, if an axis has a 60 mV (.060 volt) offset, -392 would be entered on a
UNIDEX 600/650 for this parameter. This is calculated by dividing the offset by the
voltage value of each step of the DAC. UNIDEX 600/650 has a 16-bit DAC (+/- 32767
counts). The voltage per bit is equal to the maximum voltage divided by the maximum
counts 20/65,536 = .0003 for a UNIDEX 600/650.
.060/(20/2
16
) = 197 counts for the UNIDEX 600/650
C.2.27. DECEL
This parameter controls the time that it takes to decelerate the current velocity to a lesser
velocity during G0 (point to point) moves and asynchronous moves while the
DECELMODE parameter specifies time-based ramping. Deceleration refers to any
decrease in velocity. The user may also specify deceleration mode parameters from within
a parts program.
This parameter is NOT used for CNC contoured motion (G1, G2, G3) (refer to
DecelTimeSec task parameter for ramping contoured moves).
C.2.28. DECELMODE
This parameter allows the user to select the type of ramping used during the deceleration
of the axis during G0 (point to point) moves and asynchronous moves. This ramping may
be time-based (using the DECEL parameter) or rate-based (using the DECELRATE
parameter). Also, the user may configure the ramping to be either linear or sinusoidal (1-
cosine). Figure C-4 serves as an aid in setting this parameter. The default for this
parameter is for a time-based linear ramp.
This parameter is not used for CNC contoured motion (G1,G2,G3) (refer to
DecelTimeSec task parameter for ramping contoured moves).
0 - Linear Ramping - Time Based
1 - (1-Cosine) Ramping - Time Based
2 - Linear Ramping - Rate Based
3 - (1-Cosine) Ramping - Rate Based
The user may also specify deceleration mode parameters from within a parts program.