RMC75E Integral Output

I am using an RMC75E to control a hydraulic cylinder. The problem I am experiencing is as follows:

I issue an open loop command with a voltage of -3 volts. Integral output is zero.

I then issue a hold position command and the integral output goes immediately to -30%.

Can anyone explain what causes this ?

The Hold Current Position (5) command has a Control Behavior parameter that defines how the Control Output will behave. The default option of Standard (0) will behave as you saw. The idea is that it will try to maintain whatever the axis is doing. If, immediately before this command is issued, the axis is mostly stopped with 3V Control Output, then it would be prudent to continue with 3V, otherwise the axis would likely jump. In certain cases this behavior is not desirable, and you could then use the other Control Behavior option.