No, it is not possible to mount a ZB5 head on an XACA pendant control station. Only the dedicated XACA**** booted operators and ZA2B type pushbuttons, switches and pilot lights can be used with the XACA pendant control stations.
This is because the ZB5 has not been designed for use with the specific contact blocks used in the XACA pendant (e.g. ZB2BE101, ZB2BE102, XENG****).
Regarding the XACB, XACM and XACF pendants, the new Harmony range has not been adopted as the ZA2 operators and specific contacts are still used in these enclosures. However, as these are essentially hollow enclosures it may be possible to utilise complete ZB5 (XB5) plastic operators and bodies. Please discuss your requirements with your local customer support centre should this be an option that you wish to consider.