IEC 63128:2019

IEC 63128:2019 specifies the analogue control interface of controlgear which has the function of controlling the output of the controlgear. The output of the controlgear is controlled between minimum/off and maximum values by the voltage control device sinking the controlgear current source.
This document does not specify safety requirements for the analogue interface of controlgear. Safety requirements are given in IEC 61347 (all parts).