B&R Industries Automation PC 620, User Manual

Page: 476 / 512

476
Appendix A • Glossary
Automation PC 620 User's Manual V 1.90
EPROM
Erasable PROM > (complete with ultraviolet light)
Ethernet
An IEEE 802.3 standard for networks. Ethernet uses bus or star topology and controls the traffic
on communication lines using the access procedure CSMA/CD (Carrier Sense Multiple Access
with Collision Detection). Network nodes are connected using coaxial cables, optical fiber cables
or twisted pair cabling. Data transfer on an Ethernet network takes place in frames of variable
lengths, which consist of supply and controller information as well as 1500 bytes of data. The
Ethernet standard provides baseband transfers at 10 megabit and 100 megabit per second.
ETHERNET Powerlink
is an enhancement of standard Ethernet. It enables the exchange of data under strict real-time
conditions with cycle times up to 200µs and jitter below 1µs. This makes it possible to apply
Ethernet in automation technology at all levels of communication from the control level to the
I/Os. Ethernet Powerlink was initialized by the company B&R Industrie-Elektronik and is now
managed by the open end-user and vendor association, EPSG - ETHERNET Powerlink
Standardization Group (www.ethernet-powerlink.org).
FDD
Abbreviation for »Floppy Disk Drive« Reading device for removable magnetic memory from the
early days of PC technology. Due to their sensitivity and moving components, FDDs have been
almost completely replaced by CompactFlash memory in modern automation solutions.
FIFO
An abbreviation for »First In First Out«. A queuing organization method whereby elements are
removed in the same order as they were inserted. The first element inserted is the first one
removed. Such an organization method is typical for a list of documents, which are waiting to be
printed.
Firmware
Programs stored permanently in read-only memory. Firmware is software used to operate
computer-controlled devices, which generally stays in the device throughout its lifespan or over
a long period of time. Such software includes operating systems for CPUs and application
programs for industrial-PCs as well as programmable logic controllers, (i.e. the software in a
washing machine controller). This software is written in read-only memory (ROM, PROM,
EPROM) and cannot be easily replaced.
F