Advanced options settings

Time delay before reading OPC Tags (sec)

Specify a delay (in seconds) before reading from or writing to the OPC server. If this parameter is configured, the interface connects to an OPC server and waits the specified amount of time before attempting to read data. (/sd=#).

Event Tags Source

For v1.0a OPC servers, specifies whether event tags are read from the OPC server’s cache or directly from the device. For v2.0 servers, it has no effect, because all event tag reads are from the device. (/es=CACHE or DEVICE).

Advise Groups on Creation

Some OPC servers do not return an initial value when an advise PI point is created. The resulting symptom is that, for a value that does not change often, PI Interface for OPC DA does not write a value to Data Archive when the interface starts. To determine whether your OPC server has this problem, use PI OPCClient tool to create a group, add tags, and then advise the group. If a value is not immediately returned for your tags, but adding a tag to the scan class causes a value to be returned, enable this setting. (/af=Y).

Note: Be cautioned that setting this attribute when the OPC server is returning an initial value upon advise PI point creation will lead to data loss.

Enable Mass Tag Adding

The PI OPC DA interface tells the OPC server which values it is interested in before the interface is allowed to request data for them. The interface does so by creating "groups" on the server and then adding items to the groups. The groups correspond roughly to PI scan classes and the items correspond to PI tags. The /ma parameter configures how the interface adds items to each group:

• In groups of up to 500 items at a time - Mass Tag Adding enabled (/ma=y), requiring one round-trip to the server for each group

• One at a time - Mass Tag Adding disabled (/ma=n), requiring one round-trip to the server for each item

If you have configured thousands of PI tags and notice that the interface takes a long time to start, try enabling Mass Tag Adding to reduce the time required to load points.

Note: Some OPC servers reject all the items in a group if even a single one of them is invalid. For those servers, set /ma=n to make sure the valid items are not rejected.

Depending on the network, the OPC server, and (most importantly) the point count, setting /ma=n can result in significantly slower interface startup. However, if the OPC DA interface is installed on the OPC server then the startup time may not be significantly affected.

The default setting for PI OPC DA interface is /ma=n.

GlobalLocking Not Valid

If the local PI Message Log file contains OnDataChange: Invalid group ID messages, enable this option. If the problem is resolved, the OPC server does not follow the OPC specifications. In this case, e-mail details (including OPC server vendor and version) to techsupport@osisoft.com. This flag is only meaningful for version 1.0a OPC DA. (/gl=N).

Ignore Group Status

If you see OnDataChange: Header status: in the local PI Message Log file, the group status sent by the server is invalid. To ignore the group status, enable this option. This flag is only meaningful for version 1.0a of OPC DA. (/gs=N).

Ignore Server Status

If the OPC server does not go to OPC_STATUS_RUNNING state when it is ready to send data, enable this option to direct the interface to attempt to communicate with it anyway (/is=Y).

Ignore OPC Server Access Rights

If you see “Invalid read/write mode requested” messages in the local PI Message Log file, enable this option. (/ar=N).

Use Honeywell Plantscape Failover Error Codes

Enable checking for error codes that are specific to the Honeywell Plantscape system for server-level failover. Configures the interface to fail over if it receives an error code of 0xE00483FD or 0xE00483FC on any tag. This is obsolete because Honeywell stopped using these codes after only one release. (/hwps)

Reconnect to Server Delay (sec)

Specifies how long to wait, in seconds, before attempting to reconnect to the OPC server if the connection is broken. (/rd=#).

Update Rates

Specifies the requested update rate, if different from the scan period. Select a scan class from the drop down list, enter the rate in the box to the right of the scan class, and select . The scan class, scan rate, and update rate appear in the box below the period. Only scan classes that have update rates are listed.

This option is useful when the server must have a recent value for the items but the interface does not read it very often, for example, if PI Interface for OPC DA polls for the value every 30 minutes, but the value itself must be no more than one minute old. This situation imposes more load on the OPC server than if the update rate and the scan period are the same, but it can reduce latency of values for items that need to be read less frequently. (/ur=period).