RTA's Blog
How to Pick a Communications Protocol for a Data Center
Jun
If you’re a system integrator, it’s easy to burn three weeks of commissioning time and a quarter of the project margin; Just use the wrong communications protocol in the wrong place. That’s not hard.
Every data center build hits the same wall:
- The Data Center Infrastructure Manager (DCIM) vendor wants SNMP and REST.
- The BMS vendor wants BACnet/IP. The chillers and power meters were specified by an electrical engineer who has never said the word “DCIM” out loud. He likes Modbus.
- The packaged cooling and power skids that came in on the last truck speak EtherNet/IP or PROFINET because they were built by a PLC engineer in Wisconsin.
None of them are wrong. There are good reasons for each of those communications protocols. But to connect it all in your data center, you need protocol gateways.
The Communications Protocol Map for A Typical AI Data Center
The communications protocols are not assigned by accident or random chance. Each one lives on a particular class of equipment for historical reasons that are not going to change (or if they do change, it will be a long time from now). The job of the protocol gateway is to make the equipment provide the data that the upstream system expects.
| Equipment | Communication Protocol It Speaks | What It Usually Feeds | RTA Solution / 460 Protocol Gateway Model Family |
|---|---|---|---|
| UPS, IT PDU, IT switches | SNMP | DCIM | 460 SNMP and REST variants |
| HVAC, CRAC, CRAH, fire panels | BACnet MS/TP or BACnet/IP | BMS | 460MCBS, 460MMBS, 460MSBMS |
| Power meters, chillers, sub-meters | Modbus RTU or Modbus TCP | BMS or SCADA | 460MCBC, 460MMBC, 460MSBC |
| Packaged cooling skids, CDUs, modular power | EtherNet/IP, PROFINET | SCADA, sometimes BMS | 460ETCBS, 460PSDS |
| Edge analytics, cloud telemetry | MQTT, OPC UA | Cloud DCIM, AI platforms | RTConnect module (embedded), 460 MQTT models |
That table covers about 90% percent of the protocol gateway decisions in a typical data center. The other 10% are weird, and the Enginerds at RTA can help with those, too.
Where Software Protocol Gateways Quietly Add Cost
The software protocol gateway pitch is “one platform, all communications protocols.” The fine print: one server per area, one annual subscription per point-count tier, one Windows or Linux OS to patch and one IT person to own it.
Now, run the math on a 200-point software protocol gateway across five years and you will see the hidden costs of a software solution. Software protocol gateways:
- Carry a license fee in the low thousands per year, a server to run it and the IT labor to keep both of them happy and content.
- Move the deployment decision into IT. Facilities cannot install it without a server, and the server cannot be provisioned without a ticket.
Compare those hidden costs to the upfront cost of a hardware protocol gateway bought once for a few hundred dollars. The five-year total is usually four to ten times higher. The software vendor never volunteers that number.
RTA protocol gateways don’t require IT. They are configured from a browser by the person who already knows what the data is supposed to look like.
Why European Protocol Gateway Vendors Are A Poor Fit for US Data Center Builds
European protocol gateway vendors make solid products but they run on European times with European pricing and support models that assume a European integrator is in the loop. A US operator chasing a Q1 cutover does has no time for any of that.
RTA protocol gateways:
- Ship from US stock
- Are priced for the US market
- Supported by US engineers who pick up the phone
- Include a five-year warranty
- Do not require software licenses or subscription renewal
IEC 62443 Belongs On the Spec Sheet
Any protocol gateway sitting between the OT network and the BMS or DCIM is on a security boundary, and in 2026, that boundary must be IEC 62443-aware. RTA protocol gateways run a locked-down firmware image with a defined attack surface and no general-purpose OS underneath it. A software protocol gateway running on Windows Server requires a much longer discussion with your insurer and auditor. Most of those conversations end in a remediation budget nobody planned for.
Picking A Protocol Gateway the Right Way
Three questions answer the protocol gateway choice for ninety percent of builds:
- What communications protocol does the field equipment speak? That is set by the device manufacturer and cannot be changed.
- What communications protocol does the upstream system want? That is set by the DCIM, BMS or SCADA vendor.
- How many devices and how many points? That sets the model number.
RTA’s 460 series of protocol gateways cover nearly four thousand configurations. Use our protocol gateway selector (at the top of the page) to narrow the list and find the one that fits. Or you can always call one of our Enginerds at 800-249-1612! Frankly, that’s what I do.
