Configure Collectors

The Collector Maintenance Screen

In the Collector Maintenance page, you can add or delete collectors, start and stop data collection, and examine or modify configuration parameters for any collector in your system.

The Collector Maintenance page, shown in the following figure, lists all registered collectors at the left of the page.



The right side of the page displays parameter values for the collector you select by selecting on a name in the list.

Refer to the following topics for specific collector configuration:
  • Calculation collector
  • The File collector
  • iFIX Data Collectors
  • OPC Collector
  • OPC Classic Alarms and Events collector
  • Server-to-Server Collector
  • Simulation Data Collector
  • OSI PI Collector
  • OSI PI Distributor
  • OPCUA Data Collector
  • Windows Performance Collector
  • Wonderware Data Collector
  • ODBC Data Collector
  • MQTT Data Collector
Table 1. Action Buttons
Button Function
Recalculate Recalculate collector data for a specified period.
Add Tags Browse and add tags from this collector to the archiver.
Update Apply all parameter changes you have made on any section in this page. To cancel changes and return to the original values or settings, open a different page and then return to the Collector Maintenance page.
Delete Delete the selected collector. You can choose whether you want to delete only the collector or the collector and its tags.

Modify General Options (General Tab)

The General section contains the following sections:
  • Status
  • Description
  • Resources
Table 2. The Status Subsection
Field Description
Collection Status Field The current operating status of the collector (running, stopped, or unknown). Running means it is operating and collecting data. Stopped means that it is in pause mode and not collecting data. Unknown means that status information about the collector is unavailable at present, perhaps as a result of a lost connection between collector and server or because the collector was shut down improperly.
Collection Status Options Whether or not the collector is currently collecting data. Select the appropriate button to resume or pause data collection.
Total Events Collected This counts the total number of events collected from the data source by the collector.
Total Events Reported This counts the total number of events reported to the Historian archive from the collector. This number may not match the Total Events Collected field due to collector compression.
Table 3. Description Section
Field Description
Description The name of the selected collector.
Collector Type The type of the selected collector.
Table 4. Resources Section
Field Description
Computer Name The machine name of the computer that the collector is installed on.
Memory Buffer Size (MB) The size of the memory buffer currently assigned to the store and forward function. The memory buffer stores data during short-term or momentary interruptions of the server connection; the disk buffer handles long duration outages. To estimate the size you need for this buffer, you need to know how fast the collector is trying to send data to the server and how long the server connection is likely to be down. With those values and a safety margin, you can compute the required size of the buffer.
Note: If you enter a new value for this parameter, the change is effective the next time you restart the collector.
Minimum Free Space (MB) The minimum free disk space that must be available on the computer. If the minimum space required is not available when the collector starts, the collector will shut down.

Delete a Collector

About this task

Deleting a collector removes all of its tags from the Historian Tag Database, making them unavailable for you to browse in the future.

Procedure

  1. Select a collector name from the list of collectors, as shown in the Collector Maintenance Screen.
  2. Select the Delete button at the bottom of the page.
    A message box appears asking you to confirm the deletion.
  3. Select Yes to continue.
    If you are working in the Historian Non-Web Administrator, the following message box appears.

  4. Select Yes to delete the collector and remove all of its tags from the Historian Database.
    Select No to cancel deletion.
  5. Select OK.

The Tags Section

The Tags section, shown in the following figure, displays the following information.

Note: Not all options in the Tags section are available to all collectors.
  • Default Tag Names
  • Default Collection
  • Default Compression

Default Tag Names

If the value of the tag prefix is modified, a new set of enumerated sets prefixed with the updated value will be added to Historian server. The enumerated sets prefixed with the old value will not be deleted and will not receive any further updates.

Field Description
Add Prefix to Tag Displays a prefix, if any, that is automatically added to all tag names when you browse and pick on the specified collector.

To change the prefix, enter a new text string and select the Update button at the bottom of the page. This field applies to all collectors except File and Calculation collectors.

Naming Convention When digital sets are automatically added via the OSI PI Collector:
  • The enumerated set added to Historian is prefixed using the value configured here. For Example, if "IP- 4LJPD02." has been as configured as the tag prefix value, then the digital set with name "SYSTEMSET" in PI Historian will be added as an enumerated set with name "IP-4LJPD02.SYSTEMSET" in Historian.
  • If the value of the tag prefix is modified, then a new set of enumerated sets prefixed with the updated value will be added to Historian server. The enumerated sets prefixed with the old value will not be deleted and will not receive any later updates.
Table 5. Default Collection
Field Description
Collection Interval The time in milliseconds, seconds, minutes, or hours required to complete a poll of a given tag on the selected collector. It is also used in unsolicited collection. In effect, it specifies how frequently data can be read from a tag. The collection interval can be individually configured for each tag. To change it, enter a new value.
Note: To avoid collecting repeat values with the OPC Collector when using device timestamps, specify a collection interval that is greater than the OPC Server update rate.
Collection Type Whether this collector is configured for polled data collection or unsolicited collection.
Time Assigned By Whether the timestamp for the data value is supplied by the collector or the data source. To change it, select a different type.

Default Compression

These parameters are the default compression values applied to new tags added by selecting from the Add Multiple Tags From Collector window.

Field Description
Collector Compression Whether or not collector compression is enabled as a default setting. To change it, select the other option. This option is overridden by per-tag settings.
Deadband The default setting of the collector compression deadband in absolute or percentage range values.
Compression Timeout The default setting for the collector compression time-out for tags added through the Add Multiple Tags From Collector window. You must enable the Collector Compression option to use this field.
Spike Logic Control Spike logic monitors incoming data samples for spikes in a tag's values. If spike logic is enabled, a sample of equal value to the previously archived sample is inserted into the archive in front of the spike value. For more information, refer to Spike Logic.

Spike Logic

When compression is enabled in the Historian archive, only the first instance in a series of data falling within a deadband range will be collected to the Historian archive. When that data is charted using interpolation, false values are inserted into the chart to create a smooth trend between intervals in a given time period. In most cases, interpolation gives a reasonable portrayal of the actual data for a given time period.

Unfortunately, in the event of a spike in data values, an unrealistic set of samples is created when the data is charted. Instead of showing the results of compression (the same values over a series of intervals), a rising or falling slope is created in the chart. This gives the impression that values for a given time stamp are higher or lower than they actually were. The figure below shows the difference between the raw data for a series of samples, and how the samples would be charted if data compression were enabled, assuming all values between 10 and 20 are in the deadband range.



Spike logic monitors incoming data samples for spikes in a tag's values. If spike logic is enabled, a sample of equal value to the previously archived sample is inserted into the archive in front of the spike value. The time stamp of the inserted value is determined by your polling interval. If samples are collected at 1 second intervals, the inserted sample's time stamp will be 1 second before the spike. This helps to clearly identify the spike, and retains a more accurate picture of the data leading up to it, as shown in the following figure.



Spike Logic has two configurable options: Multiplier and Interval. The Multiplier option specifies how much larger a spike value must be than the deadband range before spike logic will be invoked. For example, if a value of 3 is entered in the Multiplier field and the deadband percentage was set to 5%, spike logic will not be invoked until the difference between the spike value and the previously archived data point is 15% of the EGU range.

The Interval option specifies how many samples must have been compressed before spike logic will be invoked. For example, if the Interval field is set to 4, and 6 values have been compressed since the last archived data sample, spike logic will be invoked.

Enable or Disable Spike Logic

Procedure

  1. In the Admin app, select Collectors.
  2. Select the collector you wish to modify.
  3. Select Tags.
  4. In the Default Compression field:
    • Enable the Spike Logic Control option.
    • Disable the Spike Logic Control option.
  5. If you Enabled Spike logic control:
    1. In the Multiplier field, enter a numeric value.
    2. In the Interval field, enter a numeric value.

The Advanced Tab

The Advanced section, shown in the following figure, displays the following information.
Note: Not all options in the Advanced section are available to all collectors. If an option is disabled, it will be grayed out.
  • Collector Options
  • Collector Status Outputs (for iFIX and OPC Collectors)


Table 6. Collector Options
Field Description
On-line Tag Configuration Changes Enabling this feature allows you to make on the fly changes to tags without having to restart the collector. If you disable this option, any changes you make to tags do not affect collection until you restart the collector executable.
Browse Source Address Space Enabling this feature allows the collector to respond to requests to browse the tags in the source. You may sometimes want to disable this feature to reduce processing load on the collector.
Synchronize Timestamps to Server Time Enabling this feature automatically adjusts all outgoing data timestamps to match the server clock. This feature is not active when you configure timestamps to be supplied by the data source. Note that this does not change collector times to match the server time it adds or subtracts an increment of time to compensate for the relative difference between the clocks of the server and collector, independent of time zone or day light savings time (DST) differences. If the collector system clock is greater than 15 minutes ahead of the archiver system clock, and the Synchronize Timestamps to Server option is disabled, data will not be written to the archive.
Source/Device Timestamps Allows you to set the time source for the timestamps as either Local, or Universal Time Coordinated (UTC). This field only applies if you are using source timestamps. The collector uses this field to determine whether the timestamps coming from the data source are in local machine time or UTC.
Delay Collection at Startup Permits you to enter the number of seconds to delay collection on startup (after loading its tag configuration). The default is 2 seconds.
Table 7. Collector Status Outputs
Field Description
Rate Output Address

Address in the source database into which the collector writes the current value of the events/minute output, letting an operator or the HMI/SCADA application know the performance of the collector. This should be connected to a writable analog field. The value is written once a minute.

For an iFIX data collector, use an iFIX tag for the output address. Enter the address as NODE.TAG.FIELD (for example, MyNode.MySIM_AO.F_CV).

For an OPC Collector, use a writable OPC address in the server. Refer to your OPC documentation for more information. This value displays the same value as the Report Rate field in the collector pane in the System Statistics page of Historian Administrator.

Status Output Address

Address in the source database into which the collector writes the current value of the collector status (running, stopping, stopped, unknown, or starting) output, letting an operator or the HMI/SCADA application know the current status of the collector.

This address should be connected to a writable text field of at least 8 characters. This value is only updated upon a change in status of the collector.

For an iFIX data collector, use TX tag for the output address. Enter the address as NODE.TAG.FIELD (for example, MyNode.MyCollector_TX.A_CV).

For an OPC Collector, use an OPC address in the server. Refer to your OPC documentation for more information.

The text string usually displays either Running, Stopped, or Unknown, matching the Status column value displayed in the collector pane in the System Statistics page of Historian Administrator.

Heartbeat Output Address

Address in the source database into which the collector writes the heartbeat signal output. This address should be connected to a writable analog field.

For an iFIX data collector, use an iFIX tag for the output address. Enter the address as NODE.TAG.FIELD (for example, MyNode.MyCollector_AO.F_CV).

For an OPC Collector, use the OPC address in the server. Refer to your OPC documentation for more information.

The data collector writes the value of 1 to this location every 60 seconds while it is running. You can program the iFIX database to generate an alarm if the Heartbeat Output Address is not written to once every 60 seconds, notifying you that the data collector has stopped.

The Performance Tab

The Performance section, shown in the following figure, displays the following information:

  • Report Rate
  • Compression
  • Overruns


Note: Not all reports in the Reports section are available for all collectors.

Report Rate: This display is a trend chart that displays the average rate at which data is coming into the server from the selected collector. This is a general indicator of load on the Historian collector. Since this chart displays a slow trend of compressed data, it may not always match the instantaneous value of Report Rate displayed in the Collector panel of the System Statistics page.

Compression: This display is a trend chart that displays the effectiveness of collector compression. If the chart displays a low current value, you can widen the compression deadbands to pass fewer values and increase the effect of compression.

Overruns: This trend chart displays the value at which data overruns are occurring. This value is calculated by the following equation:
OVERRUN_PCT =OVERRUNS / ( OVERRUNS + TOTAL_EVENTS_COLLECTED )
Overruns are a count of the total number of data events not collected. In normal operation and under normal conditions, the current value should always be zero. If the current value is not zero, which indicates that data is being lost, you should take steps to reduce peak load on the system by increasing the collection interval.

Collector Redundancy

Historian includes support for collector redundancy, which decreases the likelihood of lost data due to soft- ware or hardware failures. Implementing collector redundancy ensures that collection of your data remains uninterrupted. Collector redundancy makes use of two or more collectors, gathering data from a single source. Two or more collectors may be configured in a redundant group.

All collectors in the group actively gather the same tags from a data source but only the "active" collector forwards its samples to the Historian server. The non-active collectors buffer their data against failover of the active collector. The Historian server actively monitors the health of the redundant collectors and will automatically switch to a backup if certain user-configurable trigger conditions are met.

Synchronized Configuration: The configuration for each redundant collector is managed by the Historian server. If you change the configuration on one redundant collector, all other collectors will be updated by the Historian server with the new configuration.
Note: Redundant collectors must be of the same collector type.

Offline Collectors: To reduce the possibility of lost data, a collector will immediately send its buffered data to the Historian archiver when brought online. The Historian server will ignore any data already collected to the Historian archive.

Adding Tags to a Redundant Collector: To add tags in a redundant collector system, you must add them to the primary collector. If tags are added to a redundant collector, they will not be collected until the redundant collector is taken out of the redundant system. If the primary collector is not available, you will have to add the tag manually, choosing the primary collector from the Collectors list.
Note:

  • Use Polled tags only as watchdog tags.

  • Historian redundant collector configuration does not force the active Historian collector to run on the active iFIX SCADA, since both redundant collectors provide data and alarms. Also, when both iFIX SCADAS become active, they lose connection with each other.

The Redundancy Tab

The Redundancy section, shown in the following figure, displays the following information:

  • General Settings
  • Status
  • Failover Triggers


Table 8. General Settings
Field Description
Redundant Collector If enabled, specifies that this is a redundant collector.
Backup For Specifies the primary collector.
Note: This configuration will be preserved if you disable collector redundancy. This allows you to temporarily take a redundant collector offline without losing its configuration.
Backed Up By The name of the collector providing redundancy for the selected collector.
Table 9. Status
Field Description
Collector Status (Status) The current status of this collector
Redundancy Status The current redundancy status of this collector. If a secondary collector has been activated, this will display.
Make Active Collector Now! Select this button to bring the selected collector online immediately. This is useful for testing, or in situations where the primary collector must be brought offline quickly.
Table 10. Failover Triggers
Field Description
Collector Status (Failover Triggers) If enabled, the collector will fail over if the status changes to Unknown.
Watchdog Tag Specifies a tag to use to determine the status of the collector. If the watchdog tag meets any of the conditions specified below, the secondary collector will be brought on line to replace it.
Failover on Bad Quality If enabled, the secondary collector is promoted when a data sample from the watchdog tag is received with bad quality. Failover happens on every write of a bad data sample to the watchdog, not just on the transition from good to bad quality.
Failover When Value Transitions from Zero If selected, the secondary collector is promoted when a data sample from the watchdog tag with a non-zero value is received from the primary collector. Failure happens every time when a non-zero value is received, not just when the value promotes from zero to non-zero value.
Failover When No Value Changes for X Seconds If selected, the secondary collector is promoted when no data value changes have been received within the time period specified. This could be tied into a heartbeat status indicator. Refer to Collector Status Outputs for more information. The value is checked every 5 seconds. To prevent failure, there must be a value change.

Configuring Redundant Collectors and Groups

Important information to know about the failover of Redundant Collectors:

  • In the Redundancy section of the Collectors page, you can use the Make Active Collector Now! button to manually force a failover to a backup collector.

  • In an Enterprise system, collector redundancy failover happens only after 5 minutes after a tag change. You must select the Make Active Collector Now! button after the first 5 minutes for the failover to happen.

    Also, when you shut down an active collector, it does failover. However, if there was a tag change then shutting down the active collector does not cause failover immediately, it is just delayed by 5 minutes. There will not be any data loss since the backup collector sends data for the past 15 minutes when it becomes active.

  • Failover precedent is cyclical - the last collector in a redundant group will automatically failover to the first collector in the group.
  • Configuration Manager service must be running for failover to happen in mirroring environment, If the Configuration Manager service is down, the failover will not happen.

Procedure

  1. To configure redundant collectors:
    1. In Historian Administrator, on the Collectors page, select the collector that will be the first collector in your redundant group.
    2. In the Redundancy section in the Settings section, select the Redundant Collector Enabled option and select Update.
    3. On the Collectors page, select the collector that will be your second (or backup to the first) collector in your redundant group.
    4. In the Redundancy section, in the Settings section, select the Redundant Collector Enabled option.
    5. In the Backup For list, select the collector name that this collector will back up (In this case it would be the first collector in your redundant group) and then select Update.
      You will be prompted to confirm that tags configured for the backup collector will no longer be collected.
    6. Select Yes.
      Redundancy is now configured for these two collectors. In Admin UI, on the Main page, the Redundancy Status of the first collector will be Active and the backup collector, Standby.
  2. To add more collectors to the redundant group:
    1. On the Collectors page, select the collector that will be the last collector in your redundant group.
    2. In the Redundancy section, in the Settings section, select the Redundant Collector Enabled option
    3. In the Backup For list, select the collector that backs up the currently last collector in the group and then select Update.
    4. (optional) To have collectors in the redundant group failover when the active collector???s status goes to Unknown, select the Collector Status Enabled option in the Failover Triggers subsection of the Redundancy section, and select Update.
    5. (optional) To define a watchdog tag, browse to select the tag, select the desired condition from the Failover Triggers section, and then select Update.
      Make sure you are browsing and defining the watchdog tag in the principal (or first) collector in your redundant group.