MB5904D-CT Series

4-Port Industrial Secure Modbus TCP/RTU/ASCII Gateway with Optional 3kV isolation, DIN-rail mount, dual power input, wide-temperature

  • Industrial EMC protection, wide temperature operation, -40°C~85°C
  • 2 Fast-Ethernet ports or 100/1000 SFP slots
  • 4 Software-selectable RS-232/RS-485/RS-422 serial ports, up to 921kbps
  • Bi-Directional Modbus TCP/RTU/ASCII conversion from Serial to Ethernet and viceversa, VirtualCOM support, advanced Modbus Options available
  • Isolated Redundant 12~48 VDC Power Inputs or powered (PoE models) through the Ethernet cable (802.3af)
  • Embedded security with PPTP, IPsec or OpenVPN (client/server)
  • Configuration via Web Browser/ Serial Console/ Telnet Console/ Utility
  • Rugged metal case with wall or DIN-Rail mount
  • Automatic mapping of all slaves’ data into memory, up to 64 connections
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series
MB5904D-CT Series

Diverse Hardware Infrastructure
Modbus Gateway supports the four most commonly used communication standards, RS-232/485/422, and Ethernet. The ease-of use configuration utility provided with Modbus Gateway can quickly select the hardware  interface , and easily switch to the existing communication infrastructure. Industrial EMC protection and wide temperature operation capability make MB5904D ready for every mission. And if cabling is an issue, the PoE-powered version can allow MB5904D to be powered through PoE.

Advanced embedded security and advanced features
Relax. MB5904D Modbus Gateway supports OpenVPN and IPsec VPN encryption, allowing you to safely use the device over the internet without worrying about malicious attacks, data sniffing or unintentional remote control of your Modbus slaves. On your LAN, RSTP protocol will provide an additional layer of security in case of link losses.

Switching between Modbus Protocols
Modbus Gateway supports the standard Modbus protocol and is capable of converting any Modbus protocols between Modbus TCP, Modbus RTU, and Modbus ASCII for all supported hardware interfaces. All of this, in bidirectional mode: Ethernet and Serial ends can selected to be either master or slave Modbus ID Routing. Modbus Gateway supports various types of hardware communication interfaces, Modbus protocol conversion, and Modbus ID routing. Therefore the Modbus Gateway can integrate your existing and complex Modbus hardware configuration into a simple network that can be easily managed.


Modbus Data Concentrator
The Modbus Data Concentrator performs pre-defined Modbus commands to read/write data from the slave devices via serial ports. It mirrors slave device data to its own memory. Therefore, requesting masters can receive response in a shorter period, achieving better overall efficiency.

Regular Modbus gateway


Modbus Concentrator



Environmental Limits
Operating Temperature-40°C~85°C (-40°F~185°F)
Storage Temperature-40°C~85°C (-40°F~185°F)
Ambient Relative Humidity5%~95%, 55°C (Non-condensing)
Physical CharacteristicsValue
HousingIP30 SPCC housing
Dimension (W x H x D)55 x 145 x 113 mm
InstallationDIN-Rail , Wall mount (optional kit)
Reset ButtonYes
Input VoltageDual 12 - 48VDC (non-PoE Models); or through Ethernet Cable (PoE versions)
Input Current (@ 12VDC)0.65 A @ 12 VDC
Power ConsumptionApproximately 8 W (Max)
Connector7-Pin 5.08mm Lockable Terminal Block
Power RedundancyYes
Reverse Polarity ProtectionYes
Relay Output1A @ 30 VDC (normal open)
Other Interfaces
USB Ports1
SpeedUSB 2.0
ConnectorUSB A Type
ProtocolsIPv4, ICMP, TCP, UDP, DHCP Client, SNMPv1,v2c,v3, HTTP, HTTPS, Telnet, RFC2217, RSTP, Security via PPTP, OpenVPN Client/Server or IPsec (peer-to-peer or peer-to-side) with up to 37.9Mbps VPN throughput,SMTP/TLS
ConfigurationAtop Management Utility, Web UI, Telnet
VirtualCOMWindows/Linux redirection software
Modbus Gateway Supported ModesEthernet: Modbus TCP Server/Client(or VCOM);
Serial: Modbus RTU/ASCII (master/slave)
Maximum number of Modbus clients/slavesModbus TCP: Maximum 16 clients;
Maximum 32 slave connections
Modbus concentratorOptional - please ask your ATOP Representative
Modbus redundant concentratorOptional - please ask your ATOP Representative
Serial Interface
Connector1x2 5 pin 3.81mm Terminal Block, or D-sub9 connector
ModeRS-232/422/485, software selectable
Baud Rate1,200~921,600 bps
ParityNone, Odd, Even
Data Bits7,8
Stop Bits1,2
Isolation2 KV
Network Interface
SpeedIEEE 802.3 10BaseT
IEEE 802.3u 100BaseT(X)
IEEE 802.3u for 100Base-X (SFP version only)
IEEE 802.3z for 1000Base-X (SFP version only)
PoE standard supportedIEEE 802.3 af (-PoE version only)
LAN ModeDual Subnets or Network Redundancy
Connector ports2x 10/100BASE-T(X) RJ-45 or
2x 100/1000 Base-X SFP Slots (SFP version)
ShockMIL-STD-810G Method 516.7
Drop (Freefall)MIL-STD-810G Method 516.7
VibrationMIL-STD-810G Method 514.7
MTBF14.56 Years (according to MIL-HDBK-217F)
Warranty5 Years
IEC 61000-4-2ESDContact Discharge±6kV3
IEC 61000-4-2ESDAir Discharge±8kV3
IEC 61000-4-3RS80-1000MHz10 V/m3
IEC 61000-4-3RS1.4-2.0GHz3 V/m2
IEC 61000-4-3RS2.0-2.7GHz1 V/m1
IEC 61000-4-4EFTDC Power Port±2.0kV3
IEC 61000-4-4EFTSignal Port±2.0KV4
IEC 61000-4-5SurgeDC Power PortLine-to Line±1.0KV3
IEC 61000-4-5SurgeDC Power PortLine-to Earth±1.0KV2
IEC 61000-4-5SurgeSignal PortLine-to Earth±2.0K3
IEC 61000-4-6CS0.15-80MHz10 Vrms3
IEC 61000-4-8PFMFEnclosure30 A/m4
SafetyIEC/EN 61010-1, UL61010-1, IEC/EN 61010-2-201, UL61010-2-201, EN62368-1
EMCFCC Part 15, Subpart B, Class A
EN 55032, EN 61000-3-2, EN 61000-3-3, EN 55024, EN 61000-6-2, EN 61000-6-4
SDR-75-2450500752240001G75W/3.2A DIN-Rail 24VDC power supply with 88~264VAC / 124~370VDC input
CBL-RJ45(8P)-DB9(F)-90-C50891971G8-pin RJ45-DB9 debug cable, 90cm
ADP-DB9(F)-TB559906231GFemale DB9 to Female 3.81 TB5 Converter
GDC-12059906861G120mm copper woven grounding cable
WMK-450-Black70100000000052GAluminum wall mount kit
AXGD-5854-0513522AXGD5854001GSFP Transceiver, 1250Mbps, 850nm, Multi-mode, 550m, 3.3V, -40~85°C, DDMI
AXGD-1354-0523522AXGD1354001GSFP Transceiver, 1250Mbps, 1310nm, Multi-mode, 2km, 3.3V, -40~85°C, DDMI
AXGD-1354-0533522AXGD1354011GSFP Transceiver, 1250Mbps, 1310nm, Single-mode, 10km, 3.3V, -40~85°C, DDMI
AXGD-3354-0593522AXGD3354001GSFP Transceiver, 1250Mbps, 1310nm, Single-mode, 40km, 3.3V, -40~85°C,DDMI
Ind. 4-Port Modbus Gateway, 10/100BASET(X), DB92 (RJ45)4 (DB9)
MB5904D-4P-TB-CTInd. 4-Port Modbus Gateway, 10/100BASET(X), TB52 (RJ45)4 (TB5)
MB5904D-4P-Sis-CTInd. 4-Port Modbus Gw,10/100BASET(X),3kV Isolated2 (RJ45)4 (TB5)
MB5904D-4P-PoE-DB-CTInd. 4-Port Modbus Gateway,10/100BASET(X) with PoE PD (802.3af), DB92 (RJ45)4 (DB9)
MB5904D-4P-PoE-TB-CTInd. 4-Port Modbus Gateway,10/100BASET(X) with PoE PD (802.3af), TB52 (RJ45)4 (TB5)
MB5904D-4P-PoE-Sis-CTInd. 4-Port Modbus Gateway,10/100BASET(X) with PoE PD (802.3af), TB5, 3kV Serial Isolation2 (RJ45)4 (TB5)
MB5904D-4P-G-DB-SFP-CTInd. 4-Port Modbus Gateway, 100/1000BASEX SFP Slot, DB92 (SFP)4 (DB9)
MB5904D-4P-G-TB-SFP-CTInd. 4-Port Modbus Gateway, 100/1000BASEX SFP Slot, TB52 (SFP)4 (TB5)
MB5904D-4P-G-Sis-SFP-CTInd. 4-Port Modbus Gateway, 100/1000BASEX SFP Slot, TB5, 3kV Serial Isolation2 (SFP)4 (TB5)


Version Name Time Size Download
v1.71 MB59xx CT Firmware 2023-08-17 16.3 MB


Version Name Time Size Download
v1.2 Datasheet EN 2023-11-01 423.92 KB
v1.1 Datasheet EN 2023-08-25 495.09 KB


Version Name Time Size Download
v1.5 MB59XX CT User Manual 2023-08-17 5.44 MB

Hardware Installation Guide

Version Name Time Size Download
v1.1 SE5904D/MB5904D/PG5904D Hardware Installation Guide 2023-08-17 3.81 MB

Test reports

Version Name Time Size Download
v1.0 SE-MB-PG5904D Certifications CE_FCC 2023-08-17 3.59 MB
v1.0 SE-MB-PG5904D Certifications EN61000-6-2&4 2023-08-17 6.11 MB
v1.0 SE-MB-PG5904D Certifications Environmental 2023-08-17 4.6 MB
v1.0 SE-MB-PG5904D Certifications LVD 2023-08-17 3.62 MB
v1.0 SE-MB-PG5904D Certifications UL 2023-08-17 157.83 KB