Editing Proportional–integral–derivative controller (section)

===Bumpless operation===
PID controllers are often implemented with a "bumpless" initialization feature that recalculates the integral accumulator term to maintain a consistent process output through parameter changes.<ref>{{cite web|url=http://www.controlguru.com/wp/p71.html|last=Cooper|first=Douglas|title=PI Control of the Heat Exchanger|work=Practical Process Control by Control Guru|access-date=2014-02-27}}</ref> A partial implementation is to store the integral gain times the error rather than storing the error and postmultiplying by the integral gain, which prevents discontinuous output when the I gain is changed, but not the P or D gains.