Example Applications - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 377

Central computer

Monitoring the
process status

Object history
QA data

Reader

Control commands

Goods
inwards

Stores

Paint

Drilling Addition Gluing

? ?

Paint 2

Object, material and data flow

Figure 13.50 In a decentralised system the data is carried along with the objects

database, readers in systems that operate at a rate of seconds are becoming increasingly
unable to keep pace with the process, for example in the setting of points or the
initiation of the correct processing operation (Homburg, 1996).

13.10.2.1 Benefits fromthe use of RFID systems

• Quality control: In modern production lines the quality of products is tested at

test points located at a number of stations. When the product is inspected at the
end of the production process, it must be possible to unambiguously attribute the
quality data gathered earlier to the correct object. With writable transponders that
travel with the product this is easy to achieve because all the quality data obtained
during the production process is carried with the object.

• System security: Shifting object data from the central computer to the object sig-

nificantly increases system security. Even after software crashes or failures of the
central computer, the relationship between an object and its current data can be
established anywhere and at any time. If necessary, objects can also be withdrawn
from the production process without losing the data. If the object is subsequently
put back into the process, work can continue without problems or faults occur-
ring (Weisshaupt and Gubler, 1992).

• Data security: Protecting the data stored in the transponder using a checksum

procedure (e.g. CRC, see Section 7.1) ensures the complete security of the data
that has been read. Read errors are recognised as such and the data ignored.

• Flexibility: The use of writable transponders facilitates much more flexible con-

trol of the manufacturing process. For example, the setup data for universally
programmable robots and production machines can be written to the transponder
carried with the object during the preparatory stage and is available immediately
where it is needed. Using this technique, products can be manufactured right down