Synchronizing Axes

Axis synchronization is achieved by setting either the Sync A or Sync B bit in the MODE word on the axes to be synchronized and then issuing a Go or Relative Move command to the last axis in the sync group. Up to two groups of axes can be synchronized together. If both groups are used, then one group must use the Sync A bit, and the other uses Sync B. Each group can contain as many axes as desired.

The following requirements exist when synchronizing a group of axes:

All synchronized axes must be initialized, as indicated by the Parameter Initialized bit in the STATUS word. Do this by issuing the Set Parameters command.
The low eight MODE bits of each synchronized axis must match exactly.
Synchronized commands (Go and Relative Move) must be issued to the last synchronized axis. The last synchronized axis is the highest numbered axis in the group and is displayed in the right-most column in RMCWin.
Synchronized commands issued to any synchronized axis other than the last axis are ignored.
The MODE, ACCELERATION, DECELERATION, SPEED, and COMMAND VALUE fields must be set in all axes to be synchronized before any synchronized commands are issued.

Internal to the RMC, the synchronization is accomplished as follows:

For each group of axes the axis with the longest travel distance is designated the master. If two or more synchronized axes tie for having the longest travel distance, then the first of those axes is designated the master. The other synchronized axes are designated as slaves.
The maximum speed of the master axis is limited so none of the synchronized axes will go above their requested SPEED.
The master then moves toward its destination using its own ACCELERATION, DECELERATION, and the speed calculated in the above step.
At the same time, the TARGET POSITIONS of the slave axes are ratioed to the target position of the master based on the distance each is traveling.
If any synchronized axis is halted during the move, all the other axes will halt as well.
If a new Go or Relative Move command is given to a slave axis which changes or removes the Sync bit used in the MODE word, then that slave will perform the new move, and all of the axes it was previously synchronized with will continue their synchronized move.
If a new Go or Relative Move command is given to the master axis which changes or removes the Sync bit used in the MODE word, then the master will perform the new move, but all of its previous slaves will stop.
If a new Go or Relative Move command is given to the last synchronized axis which retains the Sync bit in the MODE word, then all synchronized axes will start a new move from their current positions.

Note: Because a new Go or Relative Move command will cause the travel distance ratios to be recalculated, any change in the speeds or travel distances of any of the axes may result in a speed discontinuity in the new slave axes, although the position will always be continuous.

It is normally not possible to use RMCWin to issue commands to several axes simultaneously. However, when a command is issued to an axis that has a sync bit set, the software will automatically issue commands to all other axes that have the same sync bit set. This can only be done while in Write mode. Similarly, if a Stored Command is a synchronized command and is executed, all like-synchronized Stored Commands for the other axes will be executed simultaneously.