If you need to connect to DH+ or DH‑485 today, consider these alternatives:
While it looks like a relic today, the PCMK (PC Card Master Kit) was once an essential tool for thousands of automation engineers. In this post, we’ll cover what it was, why it mattered, and what has replaced it. pcmk card
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: . If you need to connect to DH+ or
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. The PCMK card is a fantastic piece of automation history
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.
| 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) |
| Replacement | Pros | Cons | |-------------|------|------| | (USB to DH+) | Fast, USB‑A plug, works with Windows 10/11 | Expensive ($1,500+) | | 1756‑ENBT/DHRIO (ControlLogix bridge) | Ethernet to DH+ conversion | Requires a ControlLogix rack | | ProSoft or Anybus gateways | Flexible, modern support | Additional configuration | | VM with legacy Windows 98/2000 + PCMK | Low cost if you own the card | Slow, driver headaches |