Data Diode Publisher Tag

The data diode publisher tag is paired with the Data Diode Client Tag to establish communication across a Data Diode device. It is located on the Data Diode Publisher side, within the secured network. The Data Diode Publisher tag must have an IP Address and a port number from which the Data Diode will receive and publish data. At least one Historian tag must be linked to the Data Diode Publisher tag.

The historian tags and I/O tags must be the same on both applications and have the same Unique IDs. The easiest way to do this is to create the publishing application first and copy it to reconfigure as the client application.

You must link the Historian tag(s) to the Publisher tag and Client tag by inserting custom properties in the Application Configuration.

First, find the Unique IDs of the Historian tag and either the full name or UniqueID of the Data Diode Publisher/Client tag. You can find this by locating them in the tag browser and hovering over them with your cursor. Write these down.

Next go to the Application Configuration > Edit Properties in Advanced Mode and Insert a new property.

The property name will be (The unique ID of the Historian tag)"DDPublisherID" or "DDClientID" and it's value will be (The full name or unique ID of the Data Diode Publisher/Client tag).

ex. To link a Historian tag with a unique ID of "123ztg-y\y" to a Data Diode Publisher tag with a full name of Station 1\DDP_01 you must insert 123ztg-y\yDDPublisherID = Station 1\DDP_01

To link a Historian tag with a unique ID of "4561#3_yg" to a Data Diode Client tag with a unique ID of "8_6ynG-0" you must insert 4561#3_ygDDClientID = 8_6ynG-0

If you have more than one Historian tag, repeat the process for all tags you wish to publish to Data Diode. The client-side Historian tags must have identical Unique IDs to the publisher-side Historian tags.

The global unique ID of the default system historian found in every VTScada application is "SystemHistorian"

If the server fails on the client app, there is no way for the publishing app to detect it. It will continue transmitting data until the publishing application stops or an operator intervenes. Once the server issues on the client side is resolved, you can back-track by using the Start from Date/Time button to start retransmitting from the last date captured before the failure.

Your Data Diode configuration may resemble the above diagram. The publishing tags and widgets belong in a secured network. The data is transmitted out, to a client tag on the receiving application. There is no means to transmit data into the secured network, effectively isolating it.

A Data Diode configuration requires two VTScada applications, one app on the secured network (publishing side), and one on an external network (client side).

Data Diode Publisher Properties Settings Tab

Link the port tag, set the security privilege or opt to reset the published state.

The settings tab of the Data Diode Publisher Properties.

TCP/IP Name/Address

The TCP/IP Name/Address field provides a space for you to identify the name or IP address of the server to which to connect (for example, MyRTU.com, or 198.255.32.1).

TCP/IP Port Number

The TCP/IP Port Number field refers to the port number on the host address through which communications are enabled. This information should be available from your hardware specification.

Privilege

Select a custom security privilege from this drop down to limit the access to this view to only those operators who have been granted the matching security privilege.

Reset Published State

The publishing application keeps track of data transmitted to Data Diode by using counters, state files and by utilizing a queue complete with headers and trailer checksums. In this way, VTScada can publish from where it left off if the transmission is stopped and started. To reset the published state and begin transmitting from the earliest recorded data in the historian, click Reset Published State to clear the slate.

If you select reset published state the data used as a placeholder will be deleted. You cannot undo it and you cannot speed up the process using Start from Date/Time. This widget relies on data that will be erased by resetting the published state. You will have to let the bulk sync process complete.

Data Diode Support

Data Diode Client Tag

TCP/IP Port Tags