54
Enhanced Features
WAGO-ETHERNET-Zubehör 852
852-1305 8/4-Port 100BASE-T/1000BASE-SX/LX
Manual
1.1.0
manual selection of the actual service parameters when transmitting a data packet
through a particular network. Several networks offer service precedence, which
treats high precedence traffic as more important than other traffic (generally by
accepting only traffic above certain precedence at time of high load). The most
favorable choice is a compromise between low delay, high reliability and high
throughput.
Bit 0 … 2 Precedence.
Bit 3
0 = Normal delay,
1 = Low delay.
Bit 4
0 = Normal throughput,
1 = High throughput.
Bit 5
0 = Normal reliability,
1 = High reliability.
Bit 6 … 7
Reserve for future use.
0 1 2 3 4 5 6 7 0 1 2 3
4 5 6 7
+-----+-----+-----+-----+-----+-----+-----+-----+
| PRECEDENCE | D | T | R | 0 | 0 |
+-----+-----+-----+-----+-----+-----+-----+-----+
Precedence
111 – Network Control
110 – Internetwork Control
101 – CRITIC/ECP
100 – Flash Override
011 – Flash
010 – Immediate
001 – Priority
000 – Routine
Specifying the Delay, Throughput and Reliability parameters can increase the
service cost. In many networks, preference for one parameter means a
disadvantage for another. Except for very unusual cases, two of three parameters
should be specified at most.
The “Type of Service” is used to specify the type of processing of the data packet
while it is transmitted through a network. Example mappings of the “Internet
Type of Service” to the actual service provided in networks, such as AUTODIN
II, ARPANET, SATNET and PRNET are specified in “Service Mappings”.
The Network Control precedence designation should only be used within a
network. The actual use and control of that designation depends on the respective
network. The Internetwork Control designation should only be changed by the
initiators of the gateway control.
