Delta RMC151 - Manual (Page 762)

RMC70/150 and RMCTools User Manual
This command creates a phase shift in the master position of a slave axis. The master
position is shifted in relation to the real physical position. This is analogous to opening a
coupling on the master shaft for a moment, and is used to delay or advance an axis to its
master. The phase shift is seen from the slave. The master does not know that there is a
phase shift experienced by the slave. The phase shift remains until another phasing
command changes it again.
When this command is issued, the axis must be geared and the gear ratio must be
locked. This command will not work if the axis is geared with a Gear Absolute (25)
command.
As the master moves the Master Distance from its position at the time this command
was issued, the Master Distance Offset will be added to the master position, as seen by
the slave. The Master Distance implies the direction with its sign. For example, with an
initial master position 5, a Master Distance of 2 means that the offset will happen as the
master moves from 5 up to 7. A Master Distance of -2 means that the offset happens
from 5 down to 3.
The Phasing command is related to the Geared Slave Offset (35). The Phasing command
shifts the master position as seen by the slave. The Gear Slave Offset command shifts the
slave position itself.
Phasing Example
In this example, Axis 1 (slave) is geared to Axis 0 (master) at a 1:2 ratio. Both axes start
at 0 pu. The master is moving at 5 pu/sec to 4 pu. When the master reaches 2 pu, the
following Phasing command is issued to the slave.
Master Phase Offset = 1
Master Distance = 1
The plot below shows how the slave moves.
Legend — Master Position ---- Master Position as Seen by Slave
— Slave Position — Slave Velocity — Master Velocity
The Initial Master and Slave Positions are the positions at the time the command was
issued. The dashed red line is the the Master Position as seen by the slave. The Slave
Final Position is 2.0 pu. If the Geared Slave Offset command had not been issued, it
would have been at 1.5 pu at that master position. This difference is 0.5, which is a 1:2
to ratio of the Master Distance. Therefore, the Phasing command shifted the master by 1
pu, as seen by the slave.
Reversing Direction
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