ATOP MB5904D-CT Rugged Serial to Ethernet Modbus Gateway
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The MB5904D-CT is a 4-port advanced industrial secure Modbus TCP/RTU/ASCII gateway with a data concentrator. Its four software-selectable RS-232/422/485 ports run to 921,600 bps, and the concentrator automatically maps all slaves' data into memory across up to 64 connections. It offers two 10/100BASE-T(X) RJ-45 ports or two 100/1000 Base-X SFP slots, dual 12-48 VDC input or 802.3af PoE, and -40°C to 85°C operation.
Serial ports4 (software-selectable RS-232/RS-422/RS-485)
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- Ships from the UK
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- Manufacturer's warranty
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Description
The ATOP MB5904D-CT is a four-port industrial secure Modbus gateway that links serial devices to Ethernet in a compact DIN-rail form factor. It converts between Modbus TCP and Modbus RTU or ASCII across four serial ports, and automatically maps every connected slave into local memory so masters can poll a single cached image rather than each device in turn, supporting up to 64 simultaneous connections. Optional 3 kV isolation protects the serial ports on long or noisy cable runs, dual power inputs add supply redundancy, and wide-temperature operation suits unheated cabinets and outdoor enclosures. Built-in security features make it suitable for exposed OT and utility networks. It is ideal for consolidating meters, RTUs and PLCs at the edge. See our rugged serial and Modbus gateways.
Manufacturer datasheet (PDF)
MB5904D-CT specifications
| Serial ports | 4 |
|---|---|
| Serial connector | 4x D-Sub9 RS-232/422/485 software selectable (DB models) or 4x 5.08mm 5-pin terminal block (TB models) |
| Serial isolation | 3 kV (Sis versions only) |
| Baud rate | 1,200 ~ 921,600 bps software selectable |
| Data bits / stop bits | 7, 8 / 1, 2 software selectable |
| Flow control | None, Xon/Xoff, RTS/CTS |
| Ethernet ports | 2x 10/100BASE-T(X) RJ-45 or 2x 100/1000 Base-X SFP slots (SFP version) |
| Ethernet standards | IEEE 802.3 10BaseT; 802.3u 100BaseT(X); 802.3u 100Base-X; 802.3z 1000Base-X (SFP version only) |
| Power over Ethernet | IEEE 802.3af for Power over Ethernet (PD) - PoE version only |
| LAN mode | Dual subnets or RSTP redundancy |
| USB | 1x USB A Type connector (USB 2.0) |
| Modbus data concentrator | Automatic mapping of all slaves' data into memory, up to 64 connections |
| Modbus modes | Ethernet: Modbus TCP server/client (or VCOM); Serial: Modbus RTU/ASCII (master/slave) |
| Maximum clients/slaves | Modbus TCP: maximum 16 clients; maximum 32 slave connections |
| Security | PPTP, OpenVPN client/server or IPsec (peer-to-peer or peer-to-side) with up to 37.9Mbps VPN throughput |
| Input voltage | Dual 12 - 48VDC (non-PoE models); or through Ethernet cable (PoE versions) |
| Input current | 0.65 A @ 12VDC |
| Power consumption | Approximately 8 W (max) |
| Power redundancy | Yes |
| Power connector | 7-Pin 5.08mm lockable terminal block |
| Relay output | 1A @ 30 VDC (normal open) |
| Housing | IP30 SPCC housing |
| Dimensions (W x H x D) | 55 x 145 x 113 mm |
| Weight | 1000 g |
| Installation | DIN-Rail, wall mount (optional kit) |
| Operating temperature | -40°C~85°C (-40°F~185°F) |
| Storage temperature | -40°C~85°C |
| Ambient relative humidity | 5%~95%, 55°C (non-condensing) |
| Safety | IEC/EN 61010-1, UL61010-1, IEC/EN 61010-2-201, UL61010-2-201, EN62368-1 |
| MTBF | 14.56 years (MIL-HDBK-217F) |
| Warranty | 5 years |
Specifications taken from the manufacturer datasheet.
Which version do I need?
Nine ordering variants, all 4 serial ports and 2 Ethernet interfaces; part numbers are quoted by ATOP headquarters. Serial connector: -DB (4x DB9), -TB (4x TB5), -Sis (4x TB5 with 3 kV isolation). Ethernet: RJ45 versions (MB5904D-4P-...), SFP versions (MB5904D-4P-G-...-SFP CT, 100/1000BASE-X). PoE-powered RJ45 versions (MB5904D-4P-PoE-DB/TB/Sis CT) take power over the Ethernet cable per IEEE 802.3af.
Typical applications for the MB5904D-CT
- Polling many Modbus slaves efficiently by mirroring their data into concentrator memory
- Connecting up to four serial Modbus RTU/ASCII device chains to a Modbus TCP SCADA system
- RSTP-redundant or dual-subnet LAN segments in a plant network
- Fibre-connected cabinets using the 100/1000 Base-X SFP version
- PoE-powered installations where running separate DC power is impractical
- Secure remote access to Modbus slaves across the internet over IPsec or OpenVPN
Complete the stack
Products that work with this one — connect it, power it, and get it online.
MB5904D-CT — frequently asked questions
What does the data concentrator actually do?
It runs pre-defined Modbus commands to read and write data from the slave devices via the serial ports and mirrors that data into its own memory, so a requesting master gets a response in a shorter period. It maps all slaves' data automatically across up to 64 connections.
How many serial devices can I connect and at what speed?
Four serial ports, each software-selectable RS-232, RS-422 or RS-485, running from 1,200 to 921,600 bps. The Sis versions add 3 kV isolation.
Can I run the Ethernet side over fibre, or power it over Ethernet?
Both, but not on the same model. SFP versions provide two 100/1000 Base-X SFP slots; PoE versions take power over the Ethernet cable as an IEEE 802.3af powered device. Non-PoE models use dual redundant 12-48 VDC inputs.
How many Modbus TCP masters can it serve?
A maximum of 16 Modbus TCP clients and a maximum of 32 slave connections, with bi-directional Modbus TCP/RTU/ASCII conversion.
Does it have an alarm contact?
Yes, a relay output rated 1 A at 30 VDC, normally open. The device is IP30 SPCC housed, 55 x 145 x 113 mm, 1000 g, DIN-rail or optional wall mount.
How much does the ATOP MB5904D-CT Rugged Serial to Ethernet Modbus Gateway cost in the UK?
The ATOP MB5904D-CT Rugged Serial to Ethernet Modbus Gateway is supplied to order and priced on application. Send a quote request and we confirm the price and lead time in writing, usually the same working day. No account is needed. Indiott is a UK distributor invoicing with VAT (PSI Technologies Ltd, VAT GB 730 2340 83).
What is the lead time and delivery cost for the ATOP MB5904D-CT Rugged Serial to Ethernet Modbus Gateway?
The ATOP MB5904D-CT Rugged Serial to Ethernet Modbus Gateway is supplied to order. We confirm the lead time in writing with your quote, before you commit to anything. UK delivery is a flat £14.25 per order ex VAT, whatever the weight or how many items you order. We ship to GB and the EU and provide a VAT invoice with every order.
