Simplex 566-826 — network interface assembly that puts a Simplex 4020 panel onto a 4120 network.
Each panel on a Simplex network is a node, and a node needs a network interface board plus a plug-in media card for the physical path it uses. That is what modular means here: the board carries a left and a right port, and the cards that decide whether the node talks over copper, fibre or a leased telephone line plug into them.
- Named the 4020 Network Interface Assy, with 565-411 and 565-518, in Simplex instructions 579-182 Rev. J
- The 4020 parts list calls the same board a Network Modular Double DUART
- Wired media option 565-413, an RS-485 copper board with 18–24 AWG selection
- Fibre option 565-261, 566-376 or 746-109; modem media card 565-279 or 566-338
- Style 4 needs one media circuit, Style 7 two, one per port
Panel type separates the neighbours: 566-825 is the same assembly for the 4002, while 565-516 and 566-793 serve the 4100. Do not confuse it with the physical bridge cards that serially link two loops, 565-650 or 566-827 for the 4020 and 565-649 or 566-794 for the 4100U and 4100ES.
