AlphaPro Link Layer

The AlphaCom AMC’s port 0 is a dedicated port for the configuration PC running AlphaPro. AlphaPro uses a dedicated link layer which is effective for transport of address/memory-value information.

The AlphaPro link layer also allows “tunnelling” of standard AlphaCom data protocol messages. This is used by AlphaPro for service operations like setting the clock and reseting the exchange. AlphaPro (or another program using port 0) is a regular device, and can both send and receive data protocol messages via tunnelling. But the protocol design requires that the PC always knows when to expect a message from the exchange, and how many messages will come, so it’s not suited as a general bi-directional DP port.

Using the AlphaPro link layer is not recommended except for pure service tools where it’s natural to use a port which is not blocked by the customer’s equipment.