Where additional digital inputs and outputs are required, a range of plug in options are available to add additional Input and output connection points to the drive. OPT-2-EXTIO provides an additional three digital inputs and one relay output OPT-2-CASCD provides three relay outputs, suitable for applications such as multi pump cascade controlCompatible with Optidrive P2 & HVAC modelsIncrease the onboard I/O count of the driveEncoder feedback interface for Optidrive P2 only