Hi there, We are replacing around 300 old analog single loop controllers (F&P 4000 series) with digital equivalents. The implementation of thecontrol algoritm in the new controllers is the same, so the gain/reset/rate are transferrable from the old controllers. However, the settings on the existing controllers are set by potentiometers, which we don't necessarily trust since the electronics have likely drifted over the last 20-30 years. So rather than take the old settings from the pots, we want to calculate them from the open loop response of the controller. I was wondering if there are any existing tools for doing this kind of test? I've searched around the web with no luck. Most of the software tools that would seem to do this look like they work through through the communication port of a modern controller (which obviously doesn't exist on the old analog controllers), rather than the actual controller I/O. Right now we plan on manually injecting & bumping an input, recording the output and then busting out the pen & paper to calculate the gain etc. Is there an easier way?! Thanks.