The Integrated Ethernet Switch - SEW-Eurodrive DFE32B PROFINET IO Manual

Operating Behavior in Conjunction with PROFINET
I
6

The integrated Ethernet switch

0 0
6.2 The integrated Ethernet switch
Auto-crossing
Auto-negotiation
Monitoring the
LINK status
54
A single drive axle is represented as a module under PROFINET IO. Several submod-
ules can be plugged into this module. The submodules determine the process data in-
terface to the IO controller or the data traffic partner. Thus they have provider or con-
sumer quality. The model provides the option to plug several modules into an IO device
for multi-axis systems that have a common PROFINET IO interface. In this way, each
module again represents a single axis. Slot 0 is used as a Device Access Point (DAP)
and usually represents the IO device.
You can use the integrated Ethernet switch to achieve line topologies known from the
fieldbus technology. Other bus topologies, such as star or tree, are also possible. Ring
topologies are not supported.
INFORMATION
The number of industrial Ethernet switches connected to the line affects the telegram
runtime. If a telegram passes through the units, the telegram runtime is delayed by the
store & forward function of the Ethernet switch:
• For a telegram length of 64 bytes by approximately 10 µs (at 100 Mbit/s)
• For a telegram length of 1500 bytes by approximately 130 µs (at 100 Mbit/s)
This means that the more units a telegram has to pass through, the higher the tele-
gram runtime is.
The two ports leading out of the Ethernet switch have auto-crossing functionality. This
means that they can use both patch and cross-over cables to connect to the next Ether-
net node.
The baud rate and the duplex mode is negotiated by both Ethernet nodes when estab-
lishing the connection. For this purpose, both Ethernet ports of the PROFINET connec-
tion support an auto-negotiation functionality and work with a baud rate of either
100 Mbit or 10 Mbit in full duplex or half-duplex mode.
INFORMATION
PROFINET IO networks must be operated at a baud rate of 100 Mbit in full duplex
mode.
Both ports allow for a monitoring of the LINK status. You can set up this function via the
STEP 7 hardware configuration as follows:
• Select slot 0 in STEP 7.
• Select [Object properties] from the context menu.
• Select the "Parameters" tab.
Only set the monitoring for the port that sends data packages to other nodes and not to
the control. If a LINK DOWN is detected when the monitoring function is switched on,
the PROFINET device sends a diagnostics alarm to the control via the other port
(→ section "PROFINET alarms using the example of MOVIDRIVE
Manual – DFE32B Fieldbus Interface PROFINET IO
®
B")