Delta RMC101 - Manual (Page 203)

Rotational Mode 4.7
Controller Features 4-17
Only speeds between 0 and 32,767 can be set with this command. Also, this command cannot set
the Rotational bit in the Mode word, so another command must do this.
3. Set Speed (Unsigned) Command
This command works the same as the Set Speed (Signed) command except that only the
requested speed is changed; the requested direction cannot be changed with this command.
Therefore, the Command Value is an unsigned number between 0 and 65,535 and holds the
requested speed. The Rotational bit in the Mode word must be set prior to issuing this command.
Advantages:
Allows the speed to be set to any valid value (0 to 65,535 position units/second).
Disadvantages:
The direction cannot be changed with this command. Also, this command cannot set the Rotational
bit in the Mode word, so another command must do this.
Speed Control with Cyclic Operations
In speed control the positions will increment or decrement until the position wraps. However,
position can be reset on the fly. This is desired if there is a machine cycle that is less than 65536
position units long. If a machine cycle is 30000 units long it would be nice to reset the position to
0 when the axis gets above 29999. This way the same positions will occur at the same place in
the cycle. This can be accomplished using either a Home Input to reset the positions or an Offset
Positions command. The Home Input must be used if the absolute positions must always be the
same or if the cycle distance is not an integer number of position units. For other cases, the
Offset Positions command provides a cheaper and easier to implement way of maintaining the
relative distance between events. In either case the Event Step Table must be used to either re-
arm the Home Input or to reset the positions.
4.7 Rotational Mode
Rotational mode is specifically designed for cyclic axes. When an axis is in this mode, the
positions wrap around from the Retract Limit to the Extend Limit. One of the most common uses
for Rotational mode is speed control.
To enter or exit rotational mode, use the Set Mode (M) command or issue any of the following
motion commands with the Rotational Bit (bit 9) set or cleared:
• Go (G)
• Follow Spline Segment (f)
• Open Loop (O)
• Sine Move (~)
Note: Only the following commands can exit rotational mode: Go (G) command for Quick,
Synchronized, and Point-to-Point Moves, or a Sine Move (~).
Attempts to change the Rotational mode bit through the Set Mode (M) command will be ignored if
the axis is doing a Point-to-Point, Quick, Synchronized, or Speed Control move.