In the inspection system of the upper and lower electrode rods of the projection welding machine, each station is equipped with a projection welding machine, and the plural projection welding machines are used as slave stations in parallel and belong to the PLC management
Install an RFID tag on the upper and lower electrode rods of each projection welder, and install an RFID tag code detection device on the inner wall of the projection welder, as shown in the figure (one card reader can meet the demand).
System solutions
RFID readers and tags
This solution uses metal-resistant high-temperature industrial tags, and installs a tag on the upper and lower electrode rods of the projection welding machine. The tag contains a unique code, and each electrode is bound to a unique code, and it is not reused. The unique code can be changed before binding to the electrode rod, and the unique code of the label is not modified after binding the electrode rod.
As shown in the figure, the inner wall of the projection welder is about 20~40cm away from the upper and lower electrodes, and the upper electrode has a movable range of about 10cm. Considering that the lower electrode does not move and the upper electrode has a short movement stroke, the UHF RFID reader is selected to ensure the electrode The label is always in the sensing area to ensure that the label data can be always obtained during the working process of the electrode.
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Electrode frequency management
① PLC records the number of electrodes
The card reader itself cannot sense the number of actions of the electrode rod, so a proximity switch needs to be installed on the projection welding table to detect the welding action of the electrode rod. The PLC sets the tag’s unique code to bind with the counter. After each proximity switch action, the PLC sends an instruction to the RFID reader to make the RFID tag counter +1. After the limit value is exceeded, the projection welder will not operate, and the PLC will reach the limit value of the electrode. The unique code is sent to the MES system and alarms, and the MES system records it in the library and informs the staff to replace the electrode.
After replacing the electrode, the unique code is replaced, the bound counter is cleared, and the projection welder is allowed to move.
② MES system records the number of electrodes
The management of the number of electrodes is recorded and managed in the MES system, and the electrodes are stored in a unique code label. When each projection welder moves, the PLC will transmit the number of actions 1 together with the current unique codes of the upper and lower electrodes to the MES system.
The MES system judges whether the current number of electrode actions exceeds the limit value. If it does not exceed the limit value, it will send an allowable instruction, and the projection welder will operate. If the limit value is exceeded, a negative instruction will be sent. The projection welder will not operate, and the MES system will prompt the staff to replace the electrode.
In the above two schemes, the card reader is directly connected to the plc if the serial port type is selected, and the station projection welding machine is bound by the slave station number. If the Ethernet type is selected, it is networked through the switch, and the station projection welding is bound by the IP address. machine.
Reader selection
According to the site conditions and system requirements, we recommend the industrial-grade UHF card reader with a reading distance of 20~40cm and stable reading of the unique code of the tag.
We provides serial port (RS485, RS232) and Ethernet interface, and the communication protocol provides MODBUS RTU, MODBUS TCP, EIP, PN, etc., which is convenient for customers to choose.
The following three types of labels are initially selected, which can be adjusted according to project needs in the future:
The tags are all anti-metal types, the reading distance is greater than 30cm, the normal working temperature is -20 ~ +85 ℃, and the data is effectively stored for 50 years.
The above is the RFID electrode management system for the industrial projection welding machine system. For more RFID related information, please visit www.rfidhy.com. We will update the RFID related information as soon as possible, and look forward to your consultation and cooperation.
