A bulkhead is simply a connector that is installed through the face plate of a GracePort while the cable has one end fixed to the face plate and the other end is typically a 10' cable that goes inside the cabinet.
Bulkheads and cables are offered for a wide variety of our components, including USB, Ethernet, DB9, etc. We will oftentimes have different genders available to meet the needs of your application. For example, for DB9s bulkheads, we have every option that you could need for outside (front) and inside (back) of the cabinet, which are F/F, F/M, M/F, and M/M.
After selecting an appropriate bulkhead, you would then be able to plug the opposite gender cable into the bulkhead on the inside and an appropriate connector on the other end to plug into the PLC, variable frequency drive (VFD), switch, computer, or other device you are needing to connect to. The same is true for the front, you would plug the appropriate connector into your laptop or programming device and the other end of the cable would go into the front of the bulkhead with opposite genders.