Return to Installation of the P2L-System

Signal Processing

Signal processing

The LEDs of the P2L units indicate whether a pick has been placed in the correct or the wrong compartment. Depending on this, the processor receives feedback by the green or red LED lighting up. This feedback is generated according to the following scheme:

LED status during correct pick

LED status during correct pick

LED status faulty pick

LED status during faulty pick

Signal processing digital sensor

When a pick is set, the green LED starts to light up when a high signal with approx. 24 V DC is applied to the Set pick pin of the sensor. The PLC must send the corresponding signal . If the operation takes place, the pick indicator pin receives a high signal. The set pick time now counts down. When the operation is terminated, the signal at the pick indicator pin drops out again. The error indicator pin always sends a high signal when an access is detected without the pick being set for this compartment.

PLC signals during correct operation

PLC signals during correct operation

PLC signals error

PLC signals during error

Other possible functions of the digital sensor control are based on this basic functionality and can be implemented with the higher-level PLC.

Signal processing CAN sensor: CAN data telegram

The P2L CAN bus uses the base frame according to ISO 11898-1 / CAN protocol 2.0 A. The transmission rate of the sensor is 125 kBit/s. Only one byte of data is used in the data block, i.e. 8 of the 64 bits are used.

CAN data telegram

CAN data telegram

Message protocol

The transmission rate of the sensor is 125 kBit/s. Only one byte of data is used in the data block, i.e. 8 of the 64 bits are used.

Messages to the sensor and functionalities

Command Description
0 Switches off the LEDs and end the teaching and picking mode
1 Starts teaching process
2 Starts picking process
3 Switches red LEDs on
4 Switches green LEDs on
5 Switches red and green LEDs on
6 Sensor available? If yes: answers with 200
7 Switches off the LEDs that have been switched on.
Does not overwrite a pick or teach process.

When a picking message comes in, the corresponding command is executed and the green LED lights up.
The pick signal and the teach signal have a higher priority.

Answers of the P2L sensor

Answer Meaning
128 Sensor was teached
129 Part was “picked” (removed), if it was in picking mode
130 Error
200 The response signal of the sensor when it can be reached.

The LEDs on the P2L sensor indicate the current operating status.
In case of a picking error during the assembly process or an error during teaching, the red LED flashes cyclically.