The Server-to-Server Distributor

Overview of the Server-to-Server Distributor

The Historian Server-to-Server distributor is used to send data from a smaller Historian server to a larger, centralized Historian server. You can then use this data for reporting and analytics.

You can use either the Server-to-Server collector or the Server-to-Server distributor to send data to a central Historian. However, using the Server-to-Server distributor has the following advantages:
  • It simplifies the process of configuring tags at the destination Historian.
  • It provides more flexibility at the SCADA level for tag configuration compared to the Server-to-Server collector.
  • It allows you to manage tags both from the source and destination Historian servers, whereas the Server-to-Server collector allows you to manage tags only from the destination Historian server.
Features
Feature Capability
Browse Source for Tags Yes
Browse Source for Tag Attributes Yes
Polled Collection No
Minimum Poll Interval No
Unsolicited Collection Yes
Timestamp Resolution Yes - 100 milliseconds
Data Compression Yes
Accept Device Timestamps Yes
Floating Data Point Yes
Integer Data Yes
String Data Yes
Binary Data No
Allows VB scripting No
Python Expression Tags No

Limitations

  • The Server-to-Server distributor forwards only raw data samples, messages, and alarms. It does not perform any calculations on the data.

Workflow for Using the Server-to-Server Distributor

To use the Server-to-Server distributor, you must perform the following tasks:
Number Task Notes
1 Install the collectors on the source Historian server. This step is required. This will place the collector binaries on the machines.
2 Add an instance of the Server-to-Server distributor on the source Historian server. This step is required.
3 Start the Server-to-Server distributor This step is required.
4 Configure the Server-to-Server distributor. This step is required only if you want to change the default values.
5 Create a destination tag. You can do so by browsing for the tag, adding it manually, or copying a tag. This step is required. The naming convention of the tag is 
nodename.<name of the tag>
If configured, the tag will contain a prefix.

Configure the Server-to-Server Distributor

Procedure

  1. Access Historian Administrator on the source Historian server.
  2. Select the Server-to-Server distributor from the list of collectors, and then select Configuration.
    The Collector Specific Configuration (ServerToServerDistributor) section appears.

  3. Provide values as specified in the following table, and then select Update.
    Field Description
    Source Server The source Historian server that you want to use.
    Alarm Replication Indicates whether you want to enable or disable alarm replication. If you enable alarm replication, all collected alarm data will be transferred from the source server to the destination server. If you enable alarm replication, you also enable alarm recovery. However, if you set the Max Recovery Time value to zero, alarm recovery does not happen.
    Message Replication Indicates whether you to want to enable or disable message replication. If you enable message replication, you also enable message recovery. However, if you set the Max Recovery Time value to zero, message recovery does not happen.
    Calculation Timeout (sec) The maximum time allowed for a tag's calculation formula to execute before being terminated. The default value is 10 seconds.
    Max Recovery Time (hr) The maximum duration, in hours, for which the collector will attempt to restore data during recovery logic. The default value is 4 hours.
    Add Prefix to Messages The prefix to identify replicated messages on the destination.
    Alarms and events data will automatically have a prefix added to it with the following syntax:
    MachineName_Datasource

    For example, if your alarm is forwarded from the server Almserver12 with a data source named OPCAE, the prefix will be Almserver12_OPCAE.
    The Server-to-Server distributor is configured.