Command: Gear Velocity (31)

Supported Axes:	Position or Velocity Control Axes
Supported Control Modes:	Position PID, Position I-PD, Velocity PID, Velocity I-PD

See the Commands Overview topic for basic command information and how to issue commands from PLCs, HMIs, etc.

Command Parameters

#	Parameter Description	Range
1	Numerator	Any REAL number
2	Denominator	Any REAL number, not 0
3	Master Register Note: See Specifying a Register Address below.	Valid RMC register
4	Clutch Time (sec)	Any REAL number >0

Description

This command gears the velocity of the axis to the Master Register, using the value in this register as the master velocity. Typically the master register is the Target or Actual Velocity of another axis.

When this command is issued, the RMC uses the current gear ratio or determines the current gear ratio by comparing the master to the velocities of the slave. The gear ratio is then ramped from its current effective ratio to the requested ratio in the time specified by the Clutch Time parameter. The gear ratio is determined by the Numerator and Denominator.

This command is particularly useful when gearing an axis to a velocity reference axis. Because a velocity reference axis does not have a position, the Gear Pos (Clutch by Time) (30) position command will not work, but the Gear Velocity command will. To gear apositionto a master, use the Gear Pos (Clutch by Time) (30) command.

See the Gearing Overview topic for general information about gearing, including Gear Ratio, Clutching and possible Gear Masters.

Specifying a Register Address

When issuing this command from anywhere other than RMCTools, the addresses in the Master Register command parameter must be entered as an integer value.

RMC addresses are represented in IEC format as:

%MDfile.element, where file = file number, and element = element number.

Use the following equation to convert a register address to integer format, N:

N = file * 4096 + element

Example:

Target Generator State Bits

The Target Generator bits in the Status Bits register indicate which portion of the move the axis is currently in. These bits are useful when programming complex motion sequences.

Target Generator Done bit

Indicates the clutching is complete and the gear ratio is now locked, which occurs when the Time expires.

Target Generator State A and B bits

B	A	Description
0	0	Locked at a zero (0) ratio
0	1	Increasing the ratio (away from zero)
1	0	Locked at a non-zero ratio
1	1	Decreasing the ratio (toward zero)