DirectIndustry's multi-protocol gateway index lists 34 companies and 63 products under the "multi-protocol gateway" tag, with Winmate, Azbil and PILZ among the named brands in the index [S1].
IPROS GMS (Japan) lists 145 gateway suppliers and ranks them by category, with 7 entries tagged specifically as "Protocol Gateway" alongside broader IoT/M2M, HEMS and fieldbus units [S5].
What a Protocol Gateway Actually Does
A protocol gateway is a hardware translator that maps registers, process variables and I/O between two industrial networks, isolating each side's physical layer and timing so neither PLC nor DCS has to know the other's protocol [S4][S8].
The device sits inline on the network, not in the PLC scan cycle, which is why RTA markets its units as offloading "protocol management from PLCs, lowering CPU overhead and ensuring logic stays focused on process control" [S4].
Protocol Coverage Across the 2026 Vendor Roster
Moxa's MGate line lists Modbus TCP, PROFINET, EtherNet/IP, IEC 61850, CANopen and EtherCAT as supported protocols, positioned for energy substation and discrete-automation applications [S2].
HMS Networks' Anybus Protocol Converters are framed as a connectivity drop-in solution for connecting devices to industrial networks, with the converter line addressing the same multi-vendor bridging problem [S3].
Real Time Automation (RTA) sells more than 4,000 protocol conversion configurations and supports specific drop-in replacements such as the 515RTAENI (Allen-Bradley 1761-NET-ENI) and 515RTAAIC (1761-NET-AIC) on its catalog page [S4]. Softing's FG-200 integrates up to 4 FOUNDATION Fieldbus H1 segments into a control system via Modbus TCP or FF HSE [S1].
Hardware Form Factors Compared
RTA's five-module N-series illustrates the spec spread: dimensions run 3.88 x 2.57 x 1.06 inches (NNA4, NNA1) up to 5.40 x 3.83 x 1.19 inches (N2E, N700), and serial-port counts vary from 1 (NNA1 in single-port mode) to 2 plus a CAN bus on the N34 [S4].
All five RTA modules share 10 or 100 Mbps auto-negotiation Ethernet, 12-24 VDC power, and DIN-rail or panel mounting, with the N2E and N34 additionally carrying UL/cUL Class I Div 2 hazardous-location certification [S4].
DirectIndustry listings include DIN-rail, panel-mount, portable and IP67-sealed enclosures: the Laird Sentrius RG1 series ships in IP67 with onboard Linux for outdoor multi-protocol sensor aggregation, while Winmate's RG100-SUIT is a portable RoIP radio-over-IP kit in a rugged carrying case [S1].
Criteria Comparison: Picking Among the Main Supplier Tiers
Process engineers typically rank protocol gateway suppliers on four axes: protocol depth, hazardous-area certification, configuration tooling, and lifecycle support. Moxa, HMS Anybus, and Softing lead on protocol depth, covering Modbus TCP/RTU, PROFINET, EtherNet/IP, IEC 61850, FOUNDATION Fieldbus and BACnet in cataloged product lines [S1][S2][S3]. RTA leads on configuration tooling, advertising browser-based setup and over 4,000 conversion pairings, with UL/cUL Class I Div 2 certification on its N2E and N34 modules for hazardous-area drops [S4]. For substation-grade applications, NR Electric's PCS-9794 and INGEBAS IC3 are cataloged as protocol converters and RTUs with Form 0 and Form 4 chassis options for SAS and telecontrol [S1]. On a tight BOM, IPROS lists HEMS and IoT gateways from Japanese vendors such as iND (ECOGate-100, IOG-100-Mod) and Kazumi Electronics in the 10,000 to 100,000 yen range for LTE-M and ECHONLite-to-UPnP bridging [S5].
Use Cases by Industry and Protocol Pair
In building automation, the Pertronic BASGLX-M1 acts as a BACnet gateway between a Pertronic F220 fire-alarm panel and a BMS, with a transfer rate of 10 to 100 bits per second for alarm status traffic [S1].
In substation automation, NR Electric's PCS-9794 is described as a "communication manager that maps and translates signals between station-level SCADA/protection management units and bay-level IEDs" [S1]. In legacy brownfield work, Promwad and similar integrators build custom protocol gateways to connect legacy equipment to modern networks, pairing Qualcomm and Infineon silicon in custom designs [S6]. For more spec-driven selection guidance, the buyer's map at Protocol Gateway Selection: A Spec-First Engineer's Map lays out the same comparison axes in procurement form.
Limitations, Failure Modes, and Engineering Caveats
Protocol depth on paper does not equal depth in deployed firmware: RTA markets more than 4,000 conversion solutions, but the actual supported register count, scan rate, and diagnostic granularity vary by protocol pair and require a datasheet check per pairing [S4]. A related buyer's reference, Edge Gateway Procurement: A Spec-First Buyer's Map for 2026, draws the same line between IT/OT edge gateways and pure process-protocol translators.
MultiTech's LoRaWAN gateways, listed among top IoT gateway manufacturers, are robustness-focused but oriented to LPWAN rather than real-time process buses such as PROFINET or EtherCAT, so a LoRa unit is not a drop-in for those networks [S7]. Hazardous-location gateways such as the RTA N2E and N34 carry Class I Div 2 ratings, but that rating is not equivalent to ATEX Zone 1 or IECEx certification, and European projects should confirm the exact zone rating before specifying [S4].
Sourcing Standards and What to Verify on the Datasheet
For process plants, the datasheet-level checklist should include the supported protocol pair matrix, the maximum number of mapped tags or registers, scan-cycle latency, hazardous-location rating, and power-input range (most DIN-rail gateways in the index run 12-24 VDC) [S4].
For substation work, IEC 61850 support is non-negotiable, and Moxa and the NR Electric PCS-9794 explicitly list it [S1][S2]. For FOUNDATION Fieldbus integration, the Softing FG-200's limit of 4 H1 segments per device is the binding spec, not the protocol list alone [S1]. For real-time motion or drives, EtherCAT support is the filter to apply, and Moxa's MGate is one of the few cataloged suppliers naming it [S2].
Watch list for the next procurement cycle: HMS Anybus, Moxa MGate, RTA, Softing, NR Electric, and the broader 145-supplier IPROS index remain the active reference roster as of July 2026 [S5]. Cross-reference the DirectIndustry multi-protocol gateway index (34 companies, 63 products) and the IPROS ranking (145 manufacturers, 7 tagged as Protocol Gateway) before locking a BOM [S1][S5].
The underlying component specifications are covered under fieldbus gateway, and construction machinery and equipment.