Repeat Type E-CAM

When using the E-CAM type is Repeat type, the master-slave position curve defined by the E-CAM table is repeated like the Periodic E-CAM type, except the slave command positions are set equal at each interface where the first and last points meet to prevent sudden changes in the slave command position.

If the slave command positions of the first and last points on the E-CAM table are less than one user unit apart, they will not be set equal at each interface where the first and last points meet.

If the slave command positions of the first and last points on the E-CAM table are the same, the Repeat and Periodic types will behave identically.

The following example illustrates E-CAM control in Repeat mode.

Master Axis Position	Slave Axis Position
0	500
10000	1500
20000	1000
30000	2000

The above E-CAM table will command the slave axis based on the master axis position as shown in the following plot:

Single Turn Master Axis

The Repeat type behaves differently when the master axis is a single turn axis (set using SetSingleTurn). When the master axis is a single turn axis, the slave command position is preserved when the master axis wraps around the single turn encoder range. Thus, the slave command position will be dependent on both the master axis position and how many times the master axis wrapped around the single turn encoder range.

The following example illustrates the Repeat type when the master axis is a single turn axis. In this example, the master axis single turn encoder range is from 0 to 30000.

Master Axis Position	Slave Axis Position
0	500
10000	1500
20000	1000
30000	2000

The above E-CAM table will command the slave axis based on the master axis position as shown in the following plot:

Initial Position for Single Turn Master Axis

When E-CAM is started with the Repeat E-CAM type and a single turn master axis, the initial slave axis command position will be set to the command position of the master-slave position curve that is closest to the current slave axis command position. In the above example, if E-CAM is started when the master axis position is 20000 and the slave axis command position is -1500, the initial slave command position will be set to -2000, as shown below.

Incomplete Definition for Single Turn Master Axis

If the E-CAM type is Repeat, the master axis is a single turn axis, and the E-CAM table does not define the entire single turn encoder range of the master axis, the slave axis command positions of the first and last points in the E-CAM table will be extended to cover the entire single turn encoder range.

The following example shows the case where the E-CAM table does define the entire single turn encoder range of the master axis. In this example, the master axis single turn encoder range is from 0 to 30000.

Master Axis Position	Slave Axis Position
5000	1000
20000	4000
25000	3000

The above E-CAM table will command the slave axis based on the master axis position as shown in the following plot: