I have a PI tag that recieves near real time data of MW load on a circuit. This data varies from +ve to -ve.

I have created a pair of (totalizer) tags that will store the import(+ve) and export(-ve) half-hour average data seperately. This uses Filters of 'tag' >0 and 'tag' <0 to route the data to the correct totalizer. I end up with one tag holding -ve and the other holding +ve data. However I would like both tags to return +ve data. That could be done at reporting time but is a bit of a fag having to recognise the different tags (58 circuits altogether) and include a '-1' in the datalink formula.

Is it possible to convert the -ve data to +ve via? I wish to end up with 2 tags; one holding the average data when energy is flowing one way through the circuit and the other tag averaging energy flowing the opposite way. If the flow changes part way through the half hour there will obviously be data in both tags for that half-hour period.

Conversion Factor would fit the bill I think (setting it to '-1') but seems to accept a positive value only; for conversion of rates to a totals.

I have looked into Performance Equation tags but can't see how I could average over 30 minutes with those. One solution would be to create a PE based on the Tote but that's a bit long winded and introduces extra areas for error.

Any help gladly recieved.

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