Efficient Networks S120 manual On-the-fly homing, Search for reference, Travel to reference point

Function modules 7.9 Basic positioner

Note

In this case the direction of approach to the reference zero mark is the opposite to the axes with reference cams!

External zero mark present (p0495 ≠ 0), no reference cam (p2607 = 0):

Synchronization to an external zero mark begins as soon as the signal at binector input p2595 (start homing) is detected. The drive accelerates to the velocity, specified in parameter p2608 (zero mark approach velocity) in the direction specified by the signal of binector input p2604 (reference point approach start direction). The drive synchronizes to the first external zero mark (p0495). The drive continues to travel with the same velocity and travel is started to the reference point (refer to step 3).

Note

The velocity override is inoperative during this process.

An equivalent zero mark can be set using parameter p0495 (equivalent zero mark input terminal) and the corresponding digital input selected. As standard, for increasing actual position values, the 0/1 edge is evaluated and for decreasing position actual values, the 1/0 edge. For the equivalent zero mark, this can be inverted using parameter p0490 (invert measuring probe or equivalent zero mark).

Search for reference, step 3: Travel to reference point

Travel to the reference point is started when the drive has successfully synchronized to the reference zero mark (see step 2). Once the reference zero mark has been detected, the drive accelerates on-the-fly to the reference point approach velocity set in parameter p2611. The reference point offset (p2600), the distance between the zero mark and reference point, is extended.

If the axis has reached the reference point, then the position actual value and setpoint are set to the value specified using connector input p2598 (reference point coordinate) (as standard, connector input p2598 is connected with setting parameter p2599). The axis is then homed and the status signal r2684.11 (reference point set) set.

Note

The velocity override is inoperative during this process.

If the braking distance is longer than the reference point offset or a direction reversal is required as a result of the selected reference point offset, then after detecting the reference zero mark, the drive initially brakes to standstill and then travels back.

On-the-fly homing

The mode "flying referencing" (also known as post-referencing, positioning monitoring), which is selected using a "1" signal at binector input p2597 (select referencing type), can be used in every mode (jogging, traversing block and direct setpoint input for positioning/setting- up) and is superimposed on the currently active mode. Flying referencing can be selected both with incremental and absolute measuring systems.

264	Drive Functions
	Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4