Writing values to AspenTech IP21 Historian using iCommand

[Former Member]

We have a need to trip a plant remotely and we do this by writing a value (1 or 0) to a specific tag in IP21. From there IP21 writes that value to a Kepware OPC server which actually does the tripping. We write this value to IP21 using a asp page which uses a ADODB.command object against a DSN which points to the IP21 server.

Does anyone have any experience in updating IP21 using a xMii dataserver / iCommand combination. If not can xMii support please respond as to whether this is possible and how to go about doing it. I don't want to re-invent the wheel.

Regards

[Former Member]

Jeremy,

Thanks... problem solved. I used the ODBC data server.

Roger

[Former Member]

Jeremy,

It appears the IP21 will not allow writes thru the tag query, providing I am doing it correctly. What I did is create a tag query using a IP21 UDS connector. Set the mode to current, selected the tag I wanted to update and went to the values tab and entered the new value. Tested the query, but nothing passed to IP21.

You next suggestion was to create a IDBC connector against a ODBC DSN. I have the DSN so I created the IDBC connector and checked the status but this new connector was unavailable. Having never created a IDBC against a IP21 I probably have the parameters in the connector wrong. Can you give me the necessary params to get this connector working?

Thanks

Roger

[jcgood25]

Unless the specific tag connection supports CurrentWrite (IP21 currently does not) you cannot use the TagName.1 / TagValue.1 comination to change tag values.

The new SQL based IP21 connection should be easy enough to clone based upon Northwind, and then match up the ServerURL and JDBCDriver from your existing IP21 connection. Follow suit with the DatePrefix, DateSuffix, and InternalDateFormat as well. Don't forget username/pwd.

Regards,

Jeremy

[jcgood25]

Roger,

Have you looked at the Tag Write mode capability? CurrentWrite mode for a tag query would allow you to change a tag value in the underlying connection.

Although the standard IP21 connection may not support this, an SQL type query, similar to your ASP one should work as well. You would need to create an IDBC (SQL) connection to the SystemDSN and then use a Command mode query.

Regards,

Jeremy

[Former Member]

Jeremy,

You know the capabilities of xMii are so vast is is hard to remember them all. I forgot about the write capabilities of the tag query. I will check it out and as a alternative the IDBC connector against the DSN.

Thanks for the quick reply.

Roger