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ifm
Device Manual SmartSPS AC14 with EtherNet/IP interface (AC1421, AC1422), Firmware 3.1.2
2015-11-30
Glossary of Terms
In this slave list the AS-i master enters the
slaves with a projection error on this
→master.
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Link
A link is a cross-reference to another part in
the document or to an external document.
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LKCS
LKCS =
L
ist of
K
nown
C
TT
S
laves
In this list the CTT slaves (profile 7.4 and 7.5)
which are indicated in the LDS and whose CTT
configuration has already been read are
entered. This list is independent of the LDS,
LPS, LAS and LNACS.
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LNACS
LNACS =
L
ist of
N
ot
A
ctivated
C
TT
S
laves
In this list, the CTT slaves (profiles 7.4 and
7.5) which have been detected as CTT slaves
but not activated are entered. As soon as the
slave is entered in the LAS, it is deleted from
this list. These slaves only take part in the data
exchange until the CTT configuration has been
read.
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LPS
L
ist of
P
rojected
→
S
laves.
In this slave list the AS-i master enters the
slaves projected for this
→master.
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LSB
L
east
S
ignificant
B
it/Byte
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M
MAC-ID
MAC =
M
anufacturer‘s
A
ddress
C
ode
= manufacturer's serial number.
→ID =
Id
entifier
Every network card has a MAC address, a
clearly defined worldwide unique numerical
code, more or less a kind of serial number.
Such a MAC address is a sequence of
6 hexadecimal numbers, e.g.
"00-0C-6E-D0-02-3F".
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Master
Handles the complete organisation on the bus.
The master decides on the bus access time
and polls the
→slaves cyclically.
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Master-slave communication
AS-i strictly operates to the master-slave
principle. The master polls all slaves one after
the other in always the same order. Only one
master per network line is allowed (
→cyclical
polling).
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MBd
MegaBaud
Baud, abbrev.: Bd = unit for the data
transmission speed. Do not confuse baud with
"bits per second" (bps, bits/s). Baud indicates
the number of changes of state (steps, cycles)
per second over a transmission length. But it is
not defined how many bits per step are
transmitted. The name baud can be traced
back to the French inventor J. M. Baudot
whose code was used for telex machines.
1 MBd = 1024 x 1024 Bd = 1 048 576 Bd
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MMI
→
HMI
(
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Modbus
The Modbus protocol is a communication
protocol based on a
→master/slave
architecture and was generated by Modicon
(since 1994: Groupe Schneider) in 1979 for
communication with its PLCs. In the industry,
Modbus has become a de facto standard.
Modbus/TCP is based on
→Ethernet TCP/IP.
Modbus/TCP ports the protocol defined for the
serial interface to TCP. The
→IP address
clearly identifies each device in a network.
Therefore the slave address was used to
identify one of several logical units (unit IDs) in
a physical device. To do so, the extended
IP addressing is used.
Example: 192.168.83.28.1 means unit ID 1 on
IP address 192.168.83.28.
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MRAM
MRAM =
M
agnetoresistive
R
andom
A
ccess
M
emory
The information is stored by means of
magnetic storage elements. The property of
certain materials is used to change their
electrical resistance when exposed to
magnetic fields.
Advantages of MRAM as compared to
conventional RAM memories:
• non volatile (like FRAM), but: