Choosing an industrial networking fieldbus gateway is usually a protocol-matching exercise. You need to know what is on the device side and what is on the network side, then pick a gateway that lists the right bridge. These four open-box listings cover different starting points: one is a serial-to-PROFIBUS DP converter, one is a PROFIBUS/Ethernet bridge with a single channel, and two are Moxa 4101-MB-PBS gateways with different listed price points and descriptions.
Quick take
The decision starts with protocol. If you need a gateway between PROFIBUS and Ethernet, the Softing FG-100-PB is the lowest listed price and a one-channel bridge. If your source is an RS-232 device, the Wenglor ZAG73AN02 points to RS-232 to PROFIBUS DP. If you want a Moxa gateway with RS-232/422/485 coverage and a 12-48VDC input range, the MGATE 4101-MB-PBS carries the higher listed price. If you need Modbus-to-Profibus slave conversion, the 4101-MB-PBS listing spells out that role and includes a 230.4 Kbps rate.
Listed price comparison
| Product | Listed price | Price bar |
|---|---|---|
| WENGLOR ZAG73AN02 | USD 361.20 | |
| Softing FG-100-PB | USD 233.89 | |
| MGATE 4101-MB-PBS | Moxa | USD 969.00 | |
| 4101-MB-PBS | Moxa | USD 869.00 |
The listed price spread is $233.89 to $969.00, which leaves a $735.11 gap between the lowest and highest listed options. That spread matters when you are budgeting a gateway alongside other control-panel components.
Decision matrix
| If your setup needs... | Choose this listing |
|---|---|
| RS-232 device connected to PROFIBUS DP | WENGLOR ZAG73AN02 |
| PROFIBUS/Ethernet bridge with a single channel | Softing FG-100-PB |
| Moxa gateway with RS-232/422/485 and 12-48VDC input | MGATE 4101-MB-PBS |
| Modbus-to-Profibus slave gateway with 230.4 Kbps | 4101-MB-PBS |
WENGLOR ZAG73AN02 Fieldbus Gateway
The ZAG73AN02 is listed at USD 361.20 with a New - Open box condition. The description points to RS-232 to PROFIBUS DP, making it a candidate for setups where a serial device needs to talk to a Profibus network. The title also includes the BH0229 reference, which gives you a way to search for the same unit. Choose it if your immediate task is serial-to-Profibus DP conversion. The limitation is that the listing is focused on RS-232 to PROFIBUS DP, so treat it as a serial-to-Profibus gateway for that specific link.
Softing FG-100-PB Fieldbus Gateway
At USD 233.89, the Softing FG-100-PB is the lowest listed price in this set. It is listed as New - Open box and the title places it as a PROFIBUS/Ethernet gateway with one channel. If you need a single PROFIBUS-to-Ethernet bridge, this is the listing that matches that description directly. The price also leaves room in a project budget if the gateway is just one component. The limitation is the single-channel design: the title specifies one channel, so the gateway is presented as a single-link bridge rather than a multi-port device. Keep that scope in mind when comparing it with the higher-priced Moxa listings.
MGATE 4101-MB-PBS Moxa Fieldbus Gateway
The MGATE 4101-MB-PBS is listed at USD 969.00 with an Open box condition. The description adds RS-232/422/485 support and a 12-48VDC input range, which is useful if your control voltage is not a fixed 24V or you need to cover more than one serial standard. Choose this listing if the Moxa MGATE 4101-MB-PBS model with those serial and power details is what your cabinet calls for. The limitation is the listed price: at USD 969.00 it is the highest of the four. If you do not need the wider serial coverage or DC input range, the less expensive Moxa 4101-MB-PBS listing may cover the same model family at a lower point in the range.
4101-MB-PBS Moxa Fieldbus Gateway
The 4101-MB-PBS is listed at USD 869.00 with an Open box condition. The description specifies Modbus to Profibus slave gateway, a 1-port drop-in module, a 230.4 Kbps rate, and a 0 to 55°C operating range. Choose it if your network calls for a Modbus-to-Profibus slave gateway and you want those details present in the listing. The limitation is the price spread within the Moxa pair: USD 869.00 is $100.00 below the MGATE 4101-MB-PBS listing, but the MGATE listing adds RS-232/422/485 and 12-48VDC details. If those extra details are essential, the $100 difference points to the MGATE listing; if not, this one keeps the same model family at a lower listed price.
Final recommendation by use case
If you are bridging a single PROFIBUS segment to Ethernet and want the lowest listed price in this group, the Softing FG-100-PB is the most direct match. If you have an RS-232 device that needs to reach a PROFIBUS DP network, the Wenglor ZAG73AN02 is the listing to start with. If your control panel is built around Moxa and you want a gateway with RS-232/422/485 plus a stated 12-48VDC input range, the MGATE 4101-MB-PBS gives you those details. If your network is Modbus on one side and Profibus slave on the other, the 4101-MB-PBS includes that description with a stated 230.4 Kbps rate.
