Mitsubishi Electric QD77MS User Manual page 270

Storage item
[Md.27] Current speed
[Md.28] Axis feedrate
[Md.29] Speed-position switching
control positioning movement
amount
The "[Da.8] Command speed" used by the positioning data currently being
executed is stored.

If "[Da.8] Command speed" is set to "-1", this area stores the command speed
set by the positioning data used one step earlier.

If "[Da.8] Command speed" is set to a value other than "-1", this area stores the
command speed set by the current positioning data.

When speed change function is executed, this area stores "[Cd.14] New speed
value". (For details of change speed function, refer to Section 13.5.1.)
Refresh cycle: Immediate

The speed which is actually output as a command at that time in each axis is
stored. (May be different from the actual motor speed)
"0" is stored when the axis is at a stop.
Refresh cycle: Operation cycle
[POINT]
Refer to "[Md.22] Feedrate"

The movement amount for the position control to end after changing to position
control with the speed-position switching control is stored.
When the control method is "Reverse run: position/speed", the negative value is
stored.
Refresh cycle: Immediate
5 - 132
Chapter 5 Data Used for Positioning Control
Storage details