Lika EMC58 MT, User Manual

Page: 11 / 104

IEEE 1588 This standard defines a protocol enabling synchronisation of
clocks in distributed networked devices (e.g. connected via
Ethernet).
Input register In the MODBUS data model, an Input register is the input
data. An Input register has a 16-bit quantity, is provided by an
I/O system, and allows read-only access. Refer to page 68.
Internet The global collection of networks that are connected together
and share a common range of IP addresses.
InterNIC The organization responsible for administration of IP addresses
on the Internet.
IP The network protocol used for sending network packets over a
TCP/IP network or the Internet.
IP Address The IP Address is a 32-bit number that uniquely identifies a
host (computer or other device, such as a printer or router) on
a TCP/IP network. IP addresses are normally expressed in
dotted-decimal format, with four numbers separated by
periods, such as 192.168.123.132. An IP address has two parts.
The first part of an IP address is used as a network address, the
last part as a host address. If you take the example
192.168.123.132 and divide it into these two parts you get the
following: 192.168.123. = Network; .132 = Host. Or:
192.168.123.0 = network address; 0.0.0.132 = host address.
Refer to page 27.
Isochronous
Pertains to processes that require timing coordination to be
successful. Isochronous data transfer ensures that data flows
continuously and at a steady rate in close timing with the
ability of connected devices.
Legacy Ethernet Ethernet as standardised in IEEE 802.3 (non-deterministic
operation in non-time-critical environments).
MAC address The MAC address is an identifier unique worldwide consisting
of two parts: the first 3 bytes are the manufacturer ID and are
provided by IEE standard authority; the last three bytes
represent a consecutive number of the manufacturer. Refer to
page 27.
Master A Master is any network device that sends data requests to
Slaves.
MBAP Header The MBAP header (MODBUS Application Header) is a 7-byte
header added to the start of the message and is used on
TCP/IP to identify the MODBUS Application Data Unit. It has
the following data:
•
Transaction Identifier: 2 bytes set by the Client to
uniquely identify each request. These bytes are echoed
by the Server since its responses may not be received
in the same order as the requests.
•
Protocol Identifier: 2 bytes set by the Client, always =
00 00
•
Length: 2 bytes identifying the number of bytes in the