I don't have access to a proper data acquisition system that can sample at kHz rates and I'm not willing to buy one out of pocket.
SCADA systems and HMIs are generally not set up to poll data from PLCs faster than 1 Hz.
Using a driver for the PLC communications protocol I write all of the variables of interest to a CSV file at 10 Hz.
PLC scan times are usually 10-100Hz so while I can't capture everything the PLC sees or higher frequency components to the signals than the PLC can measure, it is happy middle ground between a proper DAQ and just using the HMI software.
In addition a DAQ wouldn't be connected to all of the PLC IO but with this system I can easily grab all the PLC tags I want, as well as internal PLC tags that are not IO points.
Most HMI software has pretty brutal plotting capabilities as well (Citect process analyst being the only one that is better than passable), so on top of getting at least 10x the resolution in the data I get to use KST which is great for zooming and panning on the plots, creating sets of plots, or different plots for specific tests.
Not all HMI software even allows plot configurations to be saved, so you can spend a lot of time just re-adding the time series to the plot and setting the scales.
The plots are used for commissioning reports and records.
Interesting and thanks! I use time historians for grid level operations, but the data coming from a single generator is somewhat limited to things like real and reactive power (among others) and the economic data is submitted in a different way.
Although we sometimes supply historians they are not usually part of the up-front controls and commissioning contract so I am not as familiar with them. Usually part of the reason the HMI software plotting capabilities are such shit is so that the HMI vendor can try to up-sell a historian.
SCADA systems and HMIs are generally not set up to poll data from PLCs faster than 1 Hz.
Using a driver for the PLC communications protocol I write all of the variables of interest to a CSV file at 10 Hz.
PLC scan times are usually 10-100Hz so while I can't capture everything the PLC sees or higher frequency components to the signals than the PLC can measure, it is happy middle ground between a proper DAQ and just using the HMI software.
In addition a DAQ wouldn't be connected to all of the PLC IO but with this system I can easily grab all the PLC tags I want, as well as internal PLC tags that are not IO points.
Most HMI software has pretty brutal plotting capabilities as well (Citect process analyst being the only one that is better than passable), so on top of getting at least 10x the resolution in the data I get to use KST which is great for zooming and panning on the plots, creating sets of plots, or different plots for specific tests.
Not all HMI software even allows plot configurations to be saved, so you can spend a lot of time just re-adding the time series to the plot and setting the scales.
The plots are used for commissioning reports and records.