dl-breadcrumbs__homedl-breadcrumb-item__separatorConfiguration and programmingdl-breadcrumb-item__separatorProgramming with CODESYSdl-breadcrumb-item__separatorCODESYS Development Systemdl-breadcrumb-item__separator...dl-breadcrumb-item__separatorReference, User Interfacedl-breadcrumb-item__separatorDialogsdl-breadcrumb-item__separatorDialog 'Properties'dl-breadcrumb-item__separatorDialog 'Properties' - 'Network Variables'
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Dialog 'Properties' - 'Network Variables'dl-permalink__symbolPermalink

Symbol: _icon_project_compare

Function: In this dialog, you define network properties for the variable list that is selected in the device tree. Furthermore, any variables in it that are declared as network variables are also available.

Call: “Context menu of variable list in device tree  Properties”, “Network Variables” tab

“Network type”

UDP

“Task”

Task of the current application that controls the variables to be sent. CODESYS always sends the variables at the end of a task cycle.

“List identifier”

Used to identify the network variable list. Must be unique

“Pack variables”

The size of the packages (telegrams) that are transmitted depends on the network type. In the case of “UDP”, a package is 256 bytes.

_cds_icon_option_activated: CODESYS bundles the variables for sending in packages in order to reduce as much as possible the number of packages to send. In the case of variables of type array or structured data types, this can lead to the splitting of the variables into multiple telegrams. As a result, data inconsistencies are possible within these variables, even if the variable size is smaller than the package size.

_cds_icon_option_deactivated: CODESYS generates one package per variable.

“Transmit checksum”

_cds_icon_option_activated: A checksum is provided for each variable package. The receiver checks the checksum to make sure that the variable definitions match from the sender and receiver. A package with non-matching checksums is not accepted.

“Acknowledgement”

_cds_icon_option_activated: CODESYS sends an acknowledgement message for each received data package. If the sender does not receive a confirmation before it sends again, then an error is written to the diagnostic structure.

Note: For the ‎NetVarUdp‎ library version 3.5.7.0 and later, a receiver channel is no longer assigned when confirmed transfer is not selected. In this way, network variable exchange is also possible between two controllers on one hardware device .

“Cyclic transmission”, “Interval”

CODESYS sends the variables within the defined interval. Example for time definition: "T#70ms".

“Transmit on change”, “Minimum gap”

_cds_icon_option_activated: CODESYS sends the variables only if their values have changed. You can use "minimum gap" to define the least amount of time between two transmissions.

“Transmit on event”, “Variable”

_cds_icon_option_activated: CODESYS sends the variables as soon as the defined variable yields ‎TRUE‎.

“Settings”

Protocol-specific settings; possible entries depend on the network library.

“Port”: Number of the port that CODESYS uses for data exchange with other network units. The “Default value” is "1202". You can change the current value in the “Value” field at any time. Select the field, press the [Space Bar], and type the value.

Caution: The other nodes in the network must define the same port. If more than one UDP connection is defined in the project, then the port numbers in all configurations are adapted to this value.

“Broadcast Adr.”: The “Default value” is 255.255.255.255, which means that data exchange will take place with all network units. You can change the current value in the “Value”: select the field, press the [space bar], and type the address or address range of a subnetwork (for example, ‎197.200.100.255‎ when communication should be with all nodes that have an IP address in the range 197.200.100.x.