Key Technical Specifications
- Manufacturer: Automation / ProSoft Technology
- Product Type: EtherNet/IP to DH+ Gateway
- Ethernet Port: 1x RJ45, 10/100 Mbps, Half/Full Duplex
- DH+ Port: 1x 3-Pin Terminal (5.08mm pitch)
- DH+ Baud Rates: 57.6K, 115.2K, 230.4K (Auto-detect)
- Power Supply: 9V to 24V DC
- Typical Power Consumption: 0.9 Watts (35mA @ 24V DC)
- Operating Temperature: -40°C to +85°C
- Configuration: Built-in Web Server (HTML5)
- Enclosure Rating: IP30, UL-94HB Flame Retardant ABS
Product Introduction
Migrating a plant off legacy Data Highway Plus (DH+) is a nightmare if you have to rewire every single PLC-5 and SLC-500 rack. The Automation ANC-100E (AN-X2-AB-DHRIO) acts as a pocket-sized translator between your modern EtherNet/IP backbone and those old DH+ networks. Instead of ripping out decades-old cabling, this module plugs directly into the existing DH+ trunk and presents the legacy devices to your new ControlLogix or SCADA system as native EtherNet/IP nodes.Engineers appreciate this gateway because it eliminates the need for expensive, obsolete AB 1784-KTX or 1784-PCMK PC interface cards. It handles the heavy lifting of protocol translation natively. The built-in web server is a massive time-saver when you’re standing in a noisy plant with a laptop, letting you configure baud rates and view diagnostics without needing proprietary software. I’ve used these to upgrade PanelView HMIs on DH+ networks without touching a single line of PLC ladder logic. Just make sure you select the correct firmware mode during setup, or it will sit there blinking at you.
Quality SOP & Tech Pitfalls
We don’t just ship these in a bubble mailer. Every ANC-100E undergoes a strict lab validation. We start with a visual inspection of the RJ45 and DH+ terminal blocks for any physical damage. Then, it goes on a live test rack where we establish an EtherNet/IP connection to a ControlLogix processor and verify data mapping to a simulated DH+ node. We use a Fluke multimeter to verify the 24V DC input regulation and check isolation. Finally, we log the firmware version and seal it in anti-static packaging.Here is the brutal reality of deploying this module: DH+ polarity matters. Even though the ANC-100E claims auto-polarity detection, I’ve seen it fail to sync on degraded, 30-year-old shielded twisted pair because the signal noise was too high. Always check your DH+ cable integrity before blaming the gateway. Also, watch out for firmware mode mismatches. This module ships with multiple firmware options. If you are connecting an EtherNet/IP HMI to a DH+ PLC, you must use the DHP firmware. Using the wrong firmware mode will result in zero communication. Always photograph the old AB 1784-KTX card’s DIP switches before pulling it, so you can match the node addressing.
Installation & Configuration Guide
- Pre-Installation: ⚠️ DE-ENERGIZE THE DH+ NETWORK IF POSSIBLE. Take high-resolution photos of the existing DH+ wiring (Red/Green/Blue wires) and any DIP switch settings on the old AB 1784-KTX card. Note the station numbers.
- Removal: Disconnect the old PC interface card or gateway. Label the DH+ trunk cables.
- Installation: Wire the DH+ trunk to the 3-pin terminal block (Red, Green, Shield). Connect 24V DC power. Plug in the RJ45 Ethernet cable to your switch. COPY THE STATION ADDRESSING. Ensure the gateway is configured to match the legacy node map.
- Power-On & Testing: Apply power and check the LED indicators. Open a web browser and navigate to the module’s IP address. Verify the DH+ baud rate matches the legacy network (usually 57.6K or 230.4K). Use RSLinx to browse the DH+ network through the EtherNet/IP driver and confirm you can see the legacy PLCs.
Compatible Replacement Models
| Model | Compatibility Tier | Notes |
|---|---|---|
| ANC-100E (AN-X2-AB-DHRIO) | ✅ Drop-in Replacement | 100% hardware and software match. Direct replacement for AB 1784-KTX/PCMK. |
| AN-X2-AB-DHRIO | ✅ Drop-in Replacement | Exact same module, just the ProSoft Technology OEM part number. |
| 1756-DHRIO | ⚠️ Software Compatible | Native ControlLogix DH+ RIO module. Requires a ControlLogix chassis and backplane. Not a direct PC/network replacement. |
| 1784-U2DHP | ❌ Hardware Mod Required | USB to DH+ adapter. Requires a PC with USB ports and specific driver installation. Not a network gateway. |
Frequently Asked Questions (FAQ)
Can I use this to connect a new EtherNet/IP HMI to an old DH+ PLC-5?
Yes, absolutely. This is one of its most common use cases. Just make sure the gateway is running the DHP firmware (not the HMI-specific firmware) and configure your EtherNet/IP HMI to communicate via the ControlLogix Ethernet driver.Does it support redundant ControlLogix processors?
Yes. The ANC-100E communicates via standard EtherNet/IP and doesn’t care which processor in a redundant pair it talks to. The ControlLogix redundancy manager handles the failover transparently.What if my DH+ network is running at 230.4K baud?
The module supports 57.6K, 115.2K, and 230.4K baud rates. It has auto-baud detection, but I highly recommend manually setting the baud rate in the web interface to match your existing network exactly. Auto-detect can sometimes take longer to sync on noisy networks.Can DH+ devices initiate communication to EtherNet/IP devices?
No. Communication must be initiated from the EtherNet/IP side. The DH+ network is essentially a passive slave in this architecture. If you need DH+ to poll an EtherNet/IP device, this module won’t do it natively.Is this the same as the ProSoft AN-X2-AB-DHRIO?
Yes. Automation is a distributor/brand for ProSoft Technology modules. The ANC-100E is simply the commercial part number for the exact same AN-X2-AB-DHRIO hardware.Do I need to change my PLC-5 ladder logic to use this?
No. The gateway acts as a transparent bridge. Your existing DH+ PLC code, I/O mapping, and HMI screens will continue to work exactly as they did before. The only change is the physical communication path.
