Historian help needed

[pturmel]

Y'all might find this topic helpful:

SQL Tall/Long vs Wide Table Structure

I am in the process of trying to collect high speed historical data to an MSSQL database. We would like to collect data to set up a predictive maintenance system. We would like to collect information like temperature, vibration, voltage, current, etc. on CNC machines on a per machine cycle/part cycle basis at a 100mS sample rate. We would then like to compare the charts based on machine/part cycle to set thresholds and detect abnormalities before they become breakdowns. We are collecting all…

Further things to consider:

• Anything you can do with a transaction group you can do with a gateway timer script or a gateway tag change event. Scripted manipulation of wide tables can perform more complicated and/or more robust handshaking with PLCs than transaction groups.

• If you only care about a particular data item's relationship to time, and you only need to store it when it changes, then it is a good candidate for the tag historian.

• If the value represents a process reading (analog perhaps) that has a bit of jitter you can ignore, then it is a very good candidate for the tag historian.

• If you care about a particular data item's relationship to other items, they probably need to be sampled and stored together. Use a wide table, not the historian. If sampling on a trigger, use OPC Read mode in the transaction group, or system.opc.read*() in a script, to ensure you have the associated data from after the trigger change.

If you need the data stored in a SQL DB in a predictable structure for non-Ignition access, avoid the tag historian. Unless you are willing to implement a web API with the webdev module to deliver data to external consumers.