BECKHOFF EtherCAT Technology Section I User Manual
Page 18
ABBREVIATIONS
I-XVIII
Slave Controller
– Technology
RJ45
FCC Registered Jack, standard Ethernet connector (8P8C)
RMII
Reduced Media Independent Interface
Router
Network component acting as a gateway based on the interpretation of the IP
address.
RSTP
Rapid Spanning Tree Protocol: Prevents packet from looping infinitely between
switches; RSTP is specified in IEEE 802.1 D (Edition 2004)
RT
Real-time. Name for a real-time protocol that can be run in Ethernet controllers
without special support.
RTC
Real-time Clock chip of PCs
RT Frames
EtherCAT Messages with EtherType 0x88A4.
RX
Receive
RXPDO
Receive PDO, i.e. Process Data that will be received by ESC20
RUN
RUN indicator (LED) for application state
SAFEOP
Safe-Operational state of EtherCAT state machine
Safety
Safety function, implemented by an electric, electronic programmable fail-safe
system that maintains the equipment in a safe state, even during certain critical
external events.
Schedule
Determines what should be transferred and when.
Services
Interaction between two components to fulfill a specific task.
Set
Access method used by a client to write data to a server.
SII
Slave Information Interface
SM
SyncManager
SNMP
Simple Network Management Protocol: SNMP is the standard Internet protocol
for management and diagnostics of network components (see also RFC 1157
and RFC 1156
).
SoE
Servo Profile over EtherCAT
SOF
Start of Frame
Ethernet SOF delimiter at the end of the preamble of Ethernet frames
SPI
Serial Peripheral Interface
Src Addr
Source Address: Source address of a message.
Store and
Forward
Currently the common operating mode in switches. Frames are first received in
their entirety, the addresses are evaluated, and then they are forwarded. This
result in considerable delays, but guarantees that defective frames are not
forwarded, causing an unnecessary increase in the bus load.
STP
Shielded Twisted Pair: Shielded cable with at least 2 core pairs to be used as
the standard EtherCAT cable.