Geo SCADA Expert: Define the point scaling - Multiplier must be greater than zero

[ntokan]

I am trying to invert the sign of an analog point by setting the multiplier in the scaling section to a negative value. However, I receive the following error:
“Invalid multiplier, must be greater than zero.”

Why does Geo SCADA not allow negative values for the multiplier? This kind of limitation is not mentioned in the help. Is there any alternative way to change the sign of an analog value? (Creating derived/calculated tags is not an option, nor changing sign in outstations)

Geo SCADA version: Geo SCADA Expert 2023 (Build 86.8986), August 2024 Update.

[sbeadle]

To 'reverse' the scale of an analogue point, enable the raw scaling using the checkbox, then enter a 'reversed' full and zero scale. The multiplier is only positive and is applied after the raw scaling.

Note that for OPC UA at least, you need to read an integer value from the source for the raw scaling to work.

[ntokan]

Unfortunately, that does not work. There is an error in that case Raw Zero Scale must be less than Raw Full Scale. 

[AndrewScott]

Not all drivers support inverted scale analog points. You've not indicated which driver you're using, but I would guess its Advanced Modbus, which doesn't support them, hence Steve's suggestion doesn't work.

The multiplier and offset fields are only designed to perform unit conversions, such as Fahrenheit to Celsius or inches to centimetres.

I can't think of any other solution apart from calculation points or logic program, which you've indicated isn't an option.