Choosing between these two fieldbus gateways starts with the protocol pair you need to connect. The WENGLOR ZAG73AN02 FIELDBUS GATEWAY BH0229 points to one side of that decision, and the 4101-MB-PBS Moxa Fieldbus Gateway points to another. Both are open-box listings, but the cheaper listing is not automatically the right one.
Quick verdict
For RS-232 to PROFIBUS DP, pick the Wenglor at USD 361.20. For Modbus-to-Profibus slave, pick the Moxa at USD 869.00.
At a glance
| Product | Listed Price | Price Bar | Condition | Protocol Role |
|---|---|---|---|---|
| WENGLOR ZAG73AN02 FIELDBUS GATEWAY BH0229 | USD 361.20 | New - Open box | RS-232 to PROFIBUS DP | |
| 4101-MB-PBS | Moxa | Fieldbus Gateway, 1-Port, 230.4 Kbps, Opened | USD 869.00 | Open box | Modbus-to-Profibus slave, 1-port, 230.4 Kbps |
The price spread between the two is $507.80, which puts the Wenglor listing 58% below the Moxa listing.
Where each product wins
The Wenglor is the cleaner match when your legacy side is RS-232 and your fieldbus target is Profibus DP. It keeps the protocol pairing straightforward. The Moxa is the cleaner match when your controller speaks Modbus and the remote side needs to appear as a Profibus slave. That is a different bridge entirely, and the Moxa listing carries the more detailed line-speed profile. Let your existing network protocol decide instead of defaulting to the first listing you see.
Product notes
Wenglor ZAG73AN02 Fieldbus Gateway
The Wenglor is the direct answer for an RS-232 to PROFIBUS DP handoff. It gives you the serial-to-fieldbus bridge for that specific protocol pairing, making it a sensible first option when your legacy device speaks RS-232 and the control network expects PROFIBUS DP. The limitation is that the listing does not state a port count or baud rate, so you are working from the protocol role rather than a numeric throughput spec. If your setup is a clean RS-232-to-Profibus DP line and you are comfortable with that scope, the Wenglor covers it. If you need a defined line speed and port count, the Moxa listing is the one carrying those numbers.
Moxa 4101-MB-PBS Fieldbus Gateway
The Moxa is the direct answer for a Modbus-to-Profibus slave gateway. The listing names one port and 230.4 Kbps, and the description calls it a drop-in module with an operating range of 0 to 55°C. That makes it easier to confirm the expected line speed before you buy. If your upstream controller speaks Modbus and the remote side needs to appear as a Profibus slave, the Moxa listing aligns with that topology. The limitation is that its stated role is Modbus-to-Profibus slave, so a pure RS-232 serial handoff is not the direct fit. If you need the tighter protocol match and the numeric line speed, the Moxa is the one.
Final choice by use case
- RS-232 to PROFIBUS DP handoff: choose the WENGLOR ZAG73AN02 FIELDBUS GATEWAY BH0229.
- Modbus-to-Profibus slave handoff: choose the 4101-MB-PBS Moxa Fieldbus Gateway.
If your line already runs Modbus, the Moxa's described role is the one to aim for; if you are bringing RS-232 into Profibus DP, the Wenglor's role matches.
