Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual - Manual (Page 283)

Publication 1784-UM003A-EN-P – June 2003
Motion Object Attributes 275
Actual Acceleration Actual Acceleration is the current instantaneously measured acceleration of an
axis, in the configured axis Position Units per second per second. It is
calculated as the current increment to the actual velocity per coarse update
interval. Actual Acceleration is a signed value — the sign (+ or -) depends on
which direction the axis is currently accelerating.
Actual Acceleration is a signed floating-point value. Its resolution does not
depend on the Averaged Velocity Timebase, but rather on the conversion
constant of the axis and the fact that the GSV/SSV resolution limit on actual
velocity is 1 feedback counts per coarse update period per coarse update
period.
Command Acceleration Command Acceleration is the commanded speed of an axis, in the configured
axis Position Units per second per second, as generated by any previous
motion instructions. It is calculated as the current increment to the command
velocity per coarse update interval. Command Acceleration is a signed value—
the sign (+ or -) depends on which direction the axis is being commanded to
move.
Command Acceleration is a signed floating-point value. Its resolution does not
depend on the Averaged Velocity Timebase, but rather on the conversion
constant of the axis and the fact that the GSV/SSV resolution limit on
command velocity is 0.00001 feedback counts per coarse update period per
coarse update period.
Watch Position Watch Position is the current set-point position of an axis, in the configured
axis Position Units, as set up in the last, most recently executed, MAW (Motion
Arm Watch) instruction for that axis. Refer to the AC Motion Instruction
Specification for a detailed description of the MAW instruction.
GSV/SSV Access Attribute Name Data Type Values
GSV Actual Acceleration REAL
Position Units / Sec
2
GSV/SSV Access Attribute Name Data Type Values
GSV Command Acceleration REAL
Position Units / Sec
2
GSV/SSV Access Attribute Name Data Type Values
GSV Watch Position REAL Position Units