• SCADALink IP100Serial-to-Ethernet Gateway, Multiport Industrial Terminal Server, Modbus Multiplexer / DF1 Multiplexer designed for SCADA and Automation Applications.


SCADALink IP100: Modbus Mux / Modbus Serial TCP Gateway / SCADA Terminal Server

The SCADALink IP100 is a Serial-to-Ethernet Gateway, Multiport Industrial Terminal Server and Modbus Multiplexer designed for SCADA and automation applications requiring serial connectivity of LAN/WAN and Internet Networks. The IP100 enables IP access to serially connected devices such as PLC’s, RTU’s, SCADA hosts, Flow Computers, Data loggers and Radio Modem systems.

Unique features such as multiple host connections and simultaneous TCP, UDP and Modbus TCP ports gives it flexibility and scalability in automation and SCADA applications.

To maintain system availability for critical operations, the IP100 can be set up to provide a redundant connection through a serial or ethernet interface. The failover provides a backup link should the primary connection between the SCADA Host and the IP100 becomes unavailable.

A built-in Monitor tool enables serial communications diagnostics by providing users with realtime protocol analysis capabilities on selected serial channels. Configuration is done via simple windows GUI or ASCII Terminal. The IP100 is a compact replacement for the SCADALink IP Gateway with additional ports and expanded functionality.

The IP100 can be configured for the following Operating Modes. It also supports multiple, simultaneous operation of these Modes.

  • Modbus IP
  • Virtual Serial Server
  • Virtual Serial Client
  • Connect
  • Serial Mux
  • Serial Master


Operating Modes

Modbus IP

Modbus IP mode allows multiple simultaneous IP connections  to a single serial port. Ports can have multiple simultaneous protocols including TCP, UDP, Modbus TCP.

Virtual Serial Server

This mode enables an IP100 serial port to be connected from a remote device via a TCP socket connection, creating a virtual serial link. The connection is bidirection; data can be initiated from either side. The remote serial port that establishes a connection with the IP100 can be another IP100 in VIrtual Serial Client mode, a terminal server in Client mode or Serial-to-IP software in Client mode.

Virtual Serial Server

Virtual Serial Client

This mode enables an IP100 serial port to connect to a remote serial port via a TCP socket connection. The connection is bidirectional; data can be initiated from either side. The remote side serial port can be another IP100 configured as Virtual Serial Server, a terminal server in Server modem mode or serial-to-IP software in Server mode.

Virtual Serial Client


This mode is used to enable a remote ethernet host to periodically interrupt communication between two serial devices connected to the IP100. Under normal circumstances, there is a birdirectional communication between devices on the 2 IP100 serial ports. If the IP100 detects a TCP socket request, then it overides the serial-to-serial communications.  While the TCP socket is established, any data from the other serial device is discarded.

Connect Mode

Serial Mux

Modbus Multiplexer mode enables multiple serial Modbus Masters to communicate to a single serial Modbus Slave port. Up to 4 hosts can connect to a single serial port.

Serial Mux

Serial Master

This IP100 mode enables a serial master to communicate to serial slaves using a variety of protocols.  In the example below, gateway A routes the message using the lookup table. It extracts the Modbus address from the message and uses it to determine the output protocol, IP address and port number.

Serial Master

DF1 Multiplexing

The IP100 supports DF1 protocol muxing to allow the sharing of Allen-Bradley PLCs. The IP100 also features mix protocol muxing, allowing Modbus and DF1 protocol to be simultaneously multiplexed to the same port.





  •   5 Configurable Serial Ports (4 RS-232, 1 RS-232/RS-485)
  •   Ethernet 100Base-T (Auto Detect)
  •   TCP, UDP, Modbus TCP
  •   Supports multiple Operating Modes
  •   Wide-range of industrial uses, such as:
    • Modbus Gateway
    • Multiplexer
    • Multiple Modbus Masters
    • DF1 Multiplexing for Allen-Bradley PLCs
    • Failover Backup Link
  •   Configurable via GUI or ASCII Terminal
  •   Protocol Monitor displays Serial Port Traffic
  •   Digital I/O for remote Comm reset or control
  •   Wide Input Voltage Input: 10 – 30VDC
  •   Power Consumption: 0.6W: 50mA @ 12V or 25mA @ 24VDC
  •   Status, Alarm, TX/RX LEDs
  •   Industrial Temp (-40 Deg. C to 70 Deg. C)
  •   CSA Class I Div 2
  •   Din Rail Mount

Optional Features

  •   I/O Capabilities when I/O Expansion Modules are used
  •   Expansion modules can be attached with variations of: AI4, A04, DI8, DO8, A8D4.


In more complex applications, the IP100 can be configured for multiple simultaneous Operating Modes.

Terminal Server / Multiplexer

The IP100 can be configured to combine both the Modbus IP and Serial Mux mode

Virtual Serial Server and Client / Modbus Serial-to-Ethernet

This system emulates a serial link using an IP100 configured as a Virtual Serial Client and another as a Virtual Serial Server to enable 2 serial devices to communicate over ethernet/internet. The drawing shows Modbus devices but the devices could use any serial protocol because the message flows directly through the gateway without change.

Multiple Virtual Server Clients

Multiple virtual server clients can be used when an application requires connection to multiple ports of the same serial device. An example is when both a SCADA Host computer and Diagnostic computer need to simultaneously connect to a SCADA radio that has a primary communication port and a diagnostics port such as an MDS radiomodem.




Popular Uses

Multiple Modbus Masters

Multiple Modbus Masters

SCADA Communications Failover with Redundant Backup Link

SCADA Failover and SCADA Redundancy

 RS232 Switching for SCADA Communications

RS232 Switching

SCADA Arbitration

Directive 17

Documentation & Software


The IP100 GUI is a windows based application used to configure, save and restore IP100 settings. In addtion, the GUI provides access to the IP100 Monitor for serial port protocol analysis and control of onboard digital I/O. It is connected to the IP100 via ethernet or serial cable to COM0 or COM1.


The IP100 has a Monitor function which enables the user to monitor serial communications traffic on any of the IP100’s 5 serial ports. The Monitor function displays in the IP100 GUI or in an ASCII Terminal connected to the IP100 and is useful for diagnosing and troubleshooting SCADA Communications.

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