Radio Frequency Identification (RFID) of Parts for Optimized Process Control

Contrinex 11/15/2014

Radio Frequency IdentificationSummary:

A German manufacturer of industrial workpiece-carrier systems uses Radio Frequency Identification (RFID) technology to identify individual carriers and initiate automated in-process washing. A read-write module, mounted at the washing station, interrogates the nylon-encased RFID tag on the approaching carrier. The customer’s control system identifies the carrier and initiates the correct washing cycle.

Customer Values:

Uninterrupted production as batch identification is highly reliable
Minimal replacement transponder costs as a result of sensor’s long service life
No restrictions on use of chemical cleaners using IP 67 or IP69K-rated transponders
Low risk of mechanical damage because of sensing distance up to 42mm

Specific Product Advantages:

Passive transponders require no power source and minimal maintenance
Transponder performance guaranteed for up to 100,000 ‘write’ cycles
ConIdent® technology provides extended sensing range ≤ 42mm
Rugged transponders with nylon or all-metal housings sealed to IP67 or IP69K
Read/write units interface directly with customer control systems

Customer Application:

During manufacture of automotive components, in-process washing is a common step in an automated production cycle. Batches of components, loaded in custom-designed, metal workpiece carriers, travel between process stations in an unordered sequence. As each carrier approaches the washing station, the customer’s control system must automatically select the correct washing cycle for the batch.

The modular design of the workpiece carriers allows them to transport more than one type of component. The carrier basket accepts a number of different inserts which are tailored for specific components. The identification system must allow component data to be stored temporarily and rewritten for each batch, as a carrier is not always used for the same component.

The production environment is harsh. RFID transponders and read/write modules are exposed to hazards that include mechanical shocks, hot water, corrosive chemicals and high-pressure jetting. Identification systems must operate continuously in this environment with ultra-high reliability.

Customer Solution:

Contrinex RTP-0501-000 50mm-diameter RFID tags with nylon housings are ideal for this application. The ConIdent® range utilizes passive transponders which require no internal power source, and a range of read/write modules rated up to IP67. The RTP-0501 provides read/write distances of up to 42mm, depending on the read/write module selected.

Each workpiece carrier has an integrated holder for an RFID tag. Tags, which clip into the holder, are interchangeable and are rated IP67 or IP69K. At the start of the production cycle, the transponder is programmed with information including component part number and batch ID.

Read/write modules on process stations read the tag on each carrier. In an automotive manufacturing plant, different types of component arrive in turn at the washing station, and the information from the RFID tag is used to select the correct washing cycle for each batch.

On completion of the complete production cycle, parts are unloaded from the carrier. The customer’s PLC control system checks the tag data against the expected value and then overwrites the data on the tag in preparation for the next batch.

Contrinex ConIdent® RFID devices allow unordered process sequencing and provide excellent service life, reliability and robustness lacking in alternative identification systems.