Configuring QoS Ethernet Packet Tagging
(Original Document)
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Description
The Ethernet communication module can be configured to perform Ethernet packet tagging. The module supports the OSI layer 3 Quality of Service (QoS) standard defined in RFC-2475. When you enable QoS, the module adds a differentiated services code point (DSCP) tag to each Ethernet packet it transmits, thereby indicating the priority of that packet.
Use the QoS page to:
The contents of the QoS page depends on the Ethernet communication module you selected for your project: TSX ETC 101 or TSX ETC 101.2.
The QoS page displays five EtherNet/IP traffic types when you are operating in Advanced Mode (see below), or two EtherNet/IP traffic types when Advanced Mode is de-selected.
To display this page:
Step
Description
1
Select the Services node in the navigation tree located on the left side of the Device Editor. The Services page opens.
2
In the Services page, set the QoS Tagging field to Enabled, then click OK or Apply. The QoS node appears in the navigation tree.
3
Select the QoS node in the navigation tree.
NOTE: Refer to the topic Configuring Properties in the Device Editor for instructions on how to edit properties.
The QoS Page for the TSX ETC 101.2 Ethernet Communication Module
The following QoS page displays the default values for the TSX ETC 101.2 module displays when operating in Advanced Mode:
The QoS Page for the TSX ETC 101 Ethernet Communication Module
The following QoS page displays the default values for the TSX ETC 101 module displays when operating in Advanced Mode:
Specifying the Source of QoS Settings
The five QoS prioritization values can be set either from the communication module’s flash memory, or in this page. To specify the QoS configuration source, set the Use value from field to either:
Setting
Description
Configuration1
The communication module uses the settings input in the Type of Traffic section of this page.
Flash1
The communication module uses the settings saved in the module’s flash memory. The fields in the Type of Traffic section are read-only.
1. Schneider Electric recommends that QoS values be set in the configuration, and not by saving settings to flash memory. Settings saved to flash memory will be lost if the module is replaced.
NOTE: You can also edit QoS configuration settings by using explicit messages to set the attributes of the QoS CIP object.
Type of Traffic Settings
QoS tagging lets you prioritize Ethernet packet streams based on the type of traffic in that stream. The communication module recognizes the traffic types described below. When the Use value from field is set to Configuration, you can edit the prioritization values in this page. Each traffic type can have a prioritization value from 0... 63.
Traffic Type
Default
DSCP Value for IO Data Scheduled Priority Messages (EtherNet/IP)
47
DSCP Value for Explicit Message (Modbus TCP & EtherNet/IP)
27
DSCP Value for IO Data Urgent Priority Messages (EtherNet/IP)1
55
DSCP Value for IO Data High Priority Messages (Modbus TCP & EtherNet/IP)1
43
DSCP Value for IO Data Low Priority Messages (EtherNet/IP)1
31
DSCP Value for Network Time Protocol Messages
59
1. Visible only when Advanced Mode is enabled.
To effectively implement QoS settings in your Ethernet network:
NOTE: The QoS settings for Scheduled, High, and Low priority messages also apply to input and output priority messages for a remote device. You can configure these settings for a remote device in the Device Editor by selecting a device connection node, then opening the connection’s General page.