The on-detector Hybrid should only be accessible during detector down time (no RHIC operation), except when the control logic for a full Hybrid stick fails (960-1680 channels).
Detector electronics replacement requires detector access. In the integrated STAR run plan the SVT information is prioritized such that access can only be granted if the SVT tracking information is degraded to a point where the TPC information is degraded as well. Simulations show that this is the case as soon as a Hybrid stick fails. A detailed access plan has to be worked out for STAR-TPC and STAR-SVT electronics.