PLC 5 AUI Ethernet port

I'm trying to find out if it is possible to use the AUI ethernet port as a programming port, but am unable to find a definitive answer.

I currently have a PLC 5/11 that I would like to connect to remotely (and collect data via Inductive Automation's Ignition SCADA software), but the serial port is already being utilized. (My normal solution for connecting to legacy equipment is to use a Moxa MGate EIP3170). I have a PLC 5/20 on the shelf that I could use instead, but can't find any good documentation on the DB-15 AUI port, other than that it was designed to be connected to a thin- or thick-wire transceiver.

I've seen instances where RJ-45 ethernet ports cannot handle programming - only messaging/data transfers (the early SLC 5/05 was such an animal).

Does anyone know for sure?

The principal purpose of the Ethernet ports on PLC-5E and SLC-5/05 controllers was HMI and online programming/editing.

Ask the guys at Inductive Automation if their implementation of Ethernet for A-B controllers includes the old "CSPv4" protocol.

The PLC-5/20E might be upgradeable to support both CSPv4 and EtherNet/IP, but these days that's only available as a remanufacturing service from RA.

The required firmware versions to use EtherNet/IP on a PLC-5E are described in RA Knowledgebase Article ID # 61405 (Access Level: Everyone).