BECKHOFF EtherCAT Technology Section I - Manual (Page 16)

ABBREVIATIONS
I-XVI Slave Controller – Technology
ISO/OSI Model ISO Open Systems Interconnection Basic Reference Model (ISO 7498):
describes the division of communication into 7 layers.
IT Information Technology: Devices and methods required for computer-aided
information processing.
LatchSignal Signal for Distributed Clocks time stamping
LED Light Emitting Diode, used as an indicator
Link/Act Link/Activity Indicator (LED)
Little Endian Data format (also Intel format). The less significant byte is transferred first when
a word is transferred. With EtherCAT, the least significant bit is the first on the
wire.
LLDP Lower Layer Discovery Protocol – provides the basis for topology discovery and
configuration definition (see IEEE802.1ab)
LRD Logical Read
LWR Logical Write
LRW Logical ReadWrite
LVDS Low Voltage Differential Signaling
M12 Connector used for industrial Ethernet
MAC Media Access Control: Specifies station access to a communication medium.
With full duplex Ethernet, any station can send data at any time; the order of
access and the response to overload are defined at the network component
level (switches).
MAC Address Media Access Control Address: Also known as Ethernet address; used to
identify an Ethernet node. The Ethernet address is 6 bytes long and is assigned
by the IEEE.
Mandatory
Services Mandatory services, parameters, objects, or attributes. These must be
implemented by every station.
MBX Mailbox
MDI Media Dependent Interface:
Use of connector Pins and Signaling (PC side)
MDI-X Media Dependent Interface (crossed):
Use of connector Pins and Signaling with crossed lines (Switch/hub side)
MI (PHY) Management Interface
MII Media Independent Interface: Standardized interface between the Ethernet
MAC and PHY.
Multicast Transmission to multiple destination stations with a frame – generally uses a
special address.
NOP No Operation
NVRAM Non-volatile random access memory, e.g. EEPROM or Flash.
Octet Term from IEC 61158 – one octet comprises exactly 8 bits.
OP Operational state of EtherCAT state machine