When you're working in industrial networking fieldbus, the gateway you choose has to match the protocols already in your control loop. Two options sit at opposite ends of the price and function spectrum: the Moxa 4101-MB-PBS, a Modbus-to-Profibus slave gateway, and the Invertek OPT-2-ETHEG-IN, an Ethernet IP fieldbus gateway module. One translates between classic fieldbus protocols; the other brings Ethernet IP into a module form. Deciding which one belongs in your cabinet starts with knowing what your network actually speaks.
Quick verdict
If your network relies on Modbus devices talking to a Profibus master, the Moxa 4101-MB-PBS is the specific gateway for that job. It has one port, runs at 230.4 Kbps, and is a drop-in module. If you need Ethernet IP connectivity from a new gateway module, the Invertek OPT-2-ETHEG-IN is the new module to consider. The two products don't compete for the same socket; they're aimed at different fieldbus systems. Pick the one that matches the protocol you need to connect.
At a glance
| Product | Listed Price | Condition | Protocol Role |
|---|---|---|---|
| Moxa 4101-MB-PBS | USD 869.00 | Open box | Modbus to Profibus slave gateway, 1-port, 230.4 Kbps |
| Invertek OPT-2-ETHEG-IN | USD 152.98 | New | Ethernet IP fieldbus gateway module |
Where each product wins
Where the Moxa wins If your control network needs a Modbus-to-Profibus bridge, the Moxa 4101-MB-PBS is the only product here built for that translation. It operates as a Profibus slave and provides a single port at 230.4 Kbps. It is built as a drop-in module, so it aims to add Profibus slave capability to an existing Modbus setup without major redesign. If you already have a Profibus master and need to bring Modbus devices onto that bus, the Moxa is the correct tool.
Where the Invertek wins The Invertek OPT-2-ETHEG-IN is the new-condition option in this comparison. It functions as an Ethernet IP fieldbus gateway module, which is a different connectivity need than Modbus-to-Profibus. If you are expanding a network with Ethernet IP and want a new module, the Invertek is the match. It also comes from Invertek's United Kingdom production.
Product notes
Moxa 4101-MB-PBS
The Moxa 4101-MB-PBS is a fieldbus gateway that translates between Modbus and Profibus by acting as a Profibus slave. With one port running at 230.4 Kbps, it is designed for a specific, focused role in an industrial networking fieldbus setup. It is a drop-in module, intended to be placed into an existing system rather than assembled from scratch. The reason to choose it is protocol support: if you need Modbus-to-Profibus conversion, this device does exactly that. The main limitation is the open-box condition; it isn't new. If your project requires factory-sealed equipment, that's a real disadvantage. Buy it when the protocol match is exactly what your network requires.
Invertek OPT-2-ETHEG-IN
The Invertek OPT-2-ETHEG-IN is an Ethernet IP fieldbus gateway module from Invertek, with the United Kingdom as its country of origin. It comes in new condition, which is a clear advantage if you want a fresh component for your panel. The reason to choose it is that it provides Ethernet IP gateway functionality in a single module, and the unit is new rather than open box. The limitation is that it is not a Modbus-to-Profibus translator; it is an Ethernet IP module, so it won't solve a Profibus network need. Choose it when Ethernet IP is the protocol you need and a new module is a priority.
Final choice by use case
Choose the Moxa 4101-MB-PBS if your industrial networking fieldbus need is specifically Modbus to Profibus, and you can work with an open-box unit. Choose the Invertek OPT-2-ETHEG-IN if you need Ethernet IP fieldbus gateway capability in a new module. Match the gateway to the protocol your automation system speaks, and you'll avoid the cost and complexity of an adapter that doesn't fit the network.
