NETLink
®
Switch
67
PPI
Point-to-point interface, interface with S7-200 systems with a maximum
baud rate of 187.5 kbps
PROFIBUS
Process Field Bus is the protocol that is used mainly for automation, e.g.
for the S7-300 and S7-400 systems with a maximum baud rate of 12 Mbps
Profinet
Standard for industrial Ethernet in automation.
Proxy
System for buffering. Requests can be answered faster via a proxy, and the
network load can also be reduced. Mainly used to separate a local area
network from the WWW.
Rack/Slot
Rack refers to the configured module rack (default: 0) and slot, to the slot
for the module in question (default CPU: 2). The default configuration for
an R/S is therefore 0/2
Retry limit
Bus parameter that determines the number of attempts will be made to call
a DP slave
RFC1006
Request for comment is a type of protocol. It defines the way an ISO
packet is transported in a TCP data packet as “
useful load
”
RJ45 socket
A network socket with 8 wires according to the RJ plug system
Router
This is a machine that ensures in a network that the data of a protocol ar-
riving at it are forwarded to the intended destination network or subnet.
Routing
Routing means a defined function that mediates messages and data be-
tween LANs, WANs, MPI, and PROFIBUS
S7-TCP/IP
Interface parameterization in the PG/PC interface that is based on TCP/IP
and that is handled via the selected network interface card of the PC
SCADA
Supervisory Control and Data Acquisition. Generic term for a type of proc-
ess visualization that includes monitoring, control, and data acquisition of
automation systems, etc.
Server
A device that provides special services at the request of clients.
Single
master
Only one master is connected to the system. The NETLink
®
family mem-
bers WLAN, Switch, and PRO Compact can also act as single masters
Slave
A station that is only permitted to exchange data with the master if re-
quested to do so by the latter.
Socket
Data links that are created by means of ->TCP or ->UDP work with sockets
for the addressing purposes. A socket consists of an IP address and a port
(cf. address: street name and house number)
Subnet mask Defines the network or host component of the IP address. It permits sub-
division of address ranges and prevents direct access to other networks.
Switch
A device that can connect multiple machines with Ethernet. Unlike a hub,
a switch is “
smart
” in that it can remember the MAC addresses that are
connected to a port and routes the traffic more efficiently than the indi-
vidual ports
TCP/IP
The Transmission Control Protocol is a transport protocol to permit data
exchange between network devices. IP is the extension for Internet Proto-
col.
Timeout
Defines a protocol instruction that is activated if a defined time has been
exceeded
Token
Is a frame for permission to transmit in a network. It is passed from master