Efficient Networks S120 manual Description, Load gear position tracking Features

Function modules 7.8 Closed-loop position control

Description

The indexed position actual value acquisition permits e.g. length measurements on parts as well as the detection of axis positions by a higher-level controller (e.g. SIMATIC S7) in addition to the position control e.g. of a belt conveyor.

Two more encoders can be operated in parallel with the encoders for actual value preprocessing and position control in order to collect actual values and measured data.

The indexed acquisition of actual values can preprocess a position actual value at each of the three encoder outputs. The parameter p2502[0..3] is used to select the encoder evaluation for position control.

The parameters of the indexed actual value acquisition are indexed four times. The indexes 1..3 are assigned to the encoder evaluations 1..3. The index 0 is assigned to position control.

The parameter r2521[0..3] can be used to retrieve the current actual values of all connected encoders. For example, the position actual value for position control in r2521[0] is identical with the value r2521[1] if the position control uses encoder evaluation 1. The signal source for a position offset can be set in parameter p2516[0..3].

The absolute encoder adjustment is initiated via p2507[0..3].2, and its successful completion is reported via p2507[0..3].3. The signal source "Reference point coordinate for the position controller" p2598[0] is interconnected with p2599 during basic positioning. The other signal sources are not interconnected in the standard configuration.

The measuring probe evaluation can be enabled for the encoder evaluation x, which is not assigned to position control, via p2509[x]. The signal sources are assigned via p2510[0..3], the edge evaluation is set via p2511[0..3]. The measured value is then available in r2523[x] if the status word for encoder x (encoder 0: r2526.0..9, encoder1: 2627.0..2, encoder2: r2628.0..2, encoder3: r2529.0..2) has the "Valid measurement" bit set.

The current values of the position actual values of the different encoders can be read out via parameter r2521[0..3]. These position actual values can be corrected with a signed value from p2513[0..3] after a 0/1 signal from the signal source in p2512[0..3].

In addition, the velocity actual value (r2522[0..3]) and the position offset for absolute encoders p2525[0..3] can be processed for each encoder by the higher-level controller.

7.8.2.4Load gear position tracking

Features

●Configuration via p2720

●Virtual multiturn via p2721

●Tolerance window for monitoring the position at switching on p2722

●Input of the load gear via p2504 and p2505

●Display via r2723

Description

Position tracking for load gearing functions in the same way as position tracking for the measuring gearbox (see "Position tracking for measuring gearbox"). Position tracking is activated via the parameter p2720.0 = 1. The position tracking of the load gear, however, is only relevant for the motor encoder (encoder 1). The load gear ratio is entered via

Drive Functions	241
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4