Emerson 0471-0128-02 manual General homing definitions

By choosing a homing method the following behaviour is determined: The homing signal (positive limit switch, negative limit switch, home switch), the direction of actuation and where appropriate the position of the index pulse.

An encircled number in Figure 7-3 to Figure 7-10 indicates the code for selection of this homing position. The direction of movement is also indicated.

There are four sources of homing signal available: These are the negative and positive limit switches, the home switch and the index pulse from an encoder.

In the diagrams of homing sequences shown below, the encoder count increases as the axis's position moves to the right, in other words the left is the minimum position and the right is the maximum position.

7.7.1General homing definitions

Method 1: Homing on negative limit switch and index pulse

Using this method as shown in Figure 7-3Homing on negative limit switch and index pulse on page 48, the initial direction of movement shall be leftward if the negative limit switch is inactive (here: low). The home position shall be at the first index pulse to the right of the position where the negative limit switch becomes inactive.

Figure 7-3 Homing on negative limit switch and index pulse

Method 2: Homing on positive limit switch and index pulse

Using this method as shown in Figure 7-4Homing on positive limit switch and index pulse on page 48, the initial direction of movement shall be rightward if the positive limit switch is inactive (here: low). The position of home shall be at the first index pulse to the left of the position where the positive limit switch becomes inactive.

Figure 7-4 Homing on positive limit switch and index pulse

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