When a machine needs to reach a drive across a fieldbus network, you're choosing between a gateway that speaks your drive's language and one that speaks to the whole network. The SEW-Eurodrive DFP21B/UOH11B is the drive-specific route: a PROFIBUS fieldbus interface made for SEW inverters. The Moxa MGATE 4101-MB-PBS is the network-agnostic route, with serial support and a wide DC supply range. Here's how to pick for your industrial networking fieldbus setup.
Quick verdict
If your line is SEW-centric and you want a direct PROFIBUS connection to the drive cabinet, the SEW DFP21B/UOH11B is the more natural pick at USD 155.00. If you need a general-purpose fieldbus gateway with serial connectivity, the Moxa MGATE 4101-MB-PBS is the right target at USD 969.00.
Fieldbus gateway comparison
| Product | Listed price | Price signal | Condition | Key details |
|---|---|---|---|---|
| Moxa MGATE 4101-MB-PBS | USD 969.00 | Open box | 1-port gateway, RS-232/422/485, 12-48 VDC | |
| SEW-Eurodrive DFP21B/UOH11B | USD 155.00 | Used | PROFIBUS DP-V1 interface for SEW inverters, SBus up to 8 drives |
Where each product wins
- Moxa MGATE 4101-MB-PBS wins when the fieldbus has to talk to a serial device. The serial options and supply design mean you can adapt it to different panel voltages and device types without changing your drive family.
- SEW-Eurodrive DFP21B/UOH11B wins when the network is going into a SEW-centric cabinet. It is the direct, drive-level connection to PROFIBUS, and the SBus topology lets one gateway reach multiple drives.
Moxa MGATE 4101-MB-PBS
The Moxa is a network-level bridge rather than a drive-specific module. It has a single port with RS-232/422/485 serial options, which matters when you need to connect different serial devices to the fieldbus. The 12-48 VDC input range gives it more flexibility at the power side, especially if your cabinet has a DC bus that isn't fixed at 24 volts. The single-port form means you get one serial connection to plan around, and the open-box condition is the trade-off you accept. If your job is purely a SEW drive talking to PROFIBUS, the SEW gateway is the more targeted solution. For a mixed-vendor network, the serial options and supply range are what make the Moxa worth considering.
SEW-Eurodrive DFP21B/UOH11B
The SEW gateway is built around a specific drive family: SEW MOVIDRIVE MDX61B and MOVITRAC B series inverters. It runs on 24 VDC and connects them to a PROFIBUS DP-V1 network via SBus, handling up to eight inverters per gateway. That makes it a strong choice for a SEW-based panel that needs one straightforward path into PROFIBUS. The trade-offs are the used condition and the fact that SEW has discontinued this model, so you are buying a specific unit rather than a factory-fresh part. Its compatibility focus is also its boundary: it is a drive-oriented interface, while the Moxa covers serial bridging across different device types. If your cabinet is built around these SEW drives, the focused design works in your favor; if you need to bridge many different device types, the Moxa's serial flexibility is more useful.
Final choice by use case
- SEW-centric retrofit: Go with the SEW-Eurodrive DFP21B/UOH11B when the cabinet is full of SEW MOVIDRIVE or MOVITRAC B drives and you want a direct PROFIBUS path.
- General serial bridge: Go with the Moxa MGATE 4101-MB-PBS when you need serial flexibility and a wider DC power range across different devices.
- Mixed-vendor line: The SEW gateway makes sense when the drive family matches; the Moxa makes sense when the network has to adapt to multiple device types.
