Ready, aim, FireWire

FireWire networks could get a bigger role in industrial equipment thanks to a new standard that targets real-time automation. Here is something you can't do right now: Connect an amplifier from Aerotech Inc. (left) on the same FireWire network as an amplifier from Ormec Systems Corp. (right) The reason is both suppliers use their own high-level protocols for controlling their equipment over FireWire networks, and the two high-level protocols don't talk to each other. The idea behind the new 1394AP standard is to define a common interface that could let FireWire equipment from different industrial vendors interoperate for real-time applications. Neither Aerotech nor Ormec has yet evaluated 1394AP. The structure of the1394AP protocol becomes evident from this diagram constructed by developers at the Fraunhofer Institute. With 1394AP, one node of the network works as an application master while the rest work as slaves. The master cyclically transmits data to the slaves. Slaves may exchange data with the master and with each other as in the case of neighboring axes in a coordinated control system. The AP part of the protocol defines only a data structure for the transmission of application-specific information. Interpretation of the data takes place in the next higher level of the protocol, which is not spelled out in AP. Fraunhofer thinks a likely candidate for this higher level of the protocol is the CAN standard. Examine any camcorder or laptop computer and you will likely find a socket for a FireWire plug. FireWire, also known as IEEE 1394, is a networking scheme devised by for use in consumer electronics. It can now be found in TVs, stereos, home-theater setups, and enumerable other kinds of multimedia accessories. FireWire has even served in automation equipment. Here it can work as an inexpensive means of networking between such devices as machine-vision