If you’ve ever worked with legacy Allen‑Bradley PLCs (Programmable Logic Controllers) from the 1990s or early 2000s, you may have come across a mysterious term: .
The PCMK card is a card—commonly called a “PC Card”—used to connect a DOS‑based or early Windows laptop to Allen‑Bradley PLCs. pcmk card
| Feature | Detail | |---------|--------| | Form factor | PCMCIA Type II | | Protocols | DH+, DH‑485, RIO | | Software | RSLinx (classic), RSLogix 5/500 | | Max nodes (DH+) | Up to 64 | | Cable required | 1784‑PCMK to 1784‑PCM5 (or similar) | If you’ve ever worked with legacy Allen‑Bradley PLCs
The PCMK card is a fantastic piece of automation history. It bridged the gap between DOS/early Windows and Rockwell’s robust industrial networks at a time when every connection felt like a small victory. Today, it’s mostly a museum piece—but if you hear an old‑timer engineer say, “Hand me the PCMK card and the Winbook laptop,” you now know exactly what they’re talking about. It bridged the gap between DOS/early Windows and