Modbus TCP Client Option (Modbus over Ethernet)

Use the Modbus TCP Client option to read (and write) Ethernet connected TCP Server device registers.

Modbus TCP Client Option Benefits
Acquire register values from one or multiple connected TCP Server devices (gas analyzers, controllers, etc)
Utilize Server registers in Program Nets similar to hardwired inputs
Write to Server device registers
Flexible and Simple configuration of TCP Server register parameters via HyperWare graphic software

Product Information


Modbus TCP Client Option

Modbus TCP Server Register Dialog

Icon Configuration Dialog for specifying Modbus TCP Server (or RTU Slave) register to read (or write).

IntelliLoggers equipped with the Modbus TCP Client option can read (and optionally write) register values from (to) other Ethernet connected Modbus TCP Server devices. Modbus TCP Client/Server communications is analogous to Modbus RTU Master/Slave operation with the difference being that the TCP Client/Server communications is performed over Ethernet instead of RS-232 or RS-485 for RTU.

1000’s of Modbus Server devices are manufactured by various companies ranging from flow computers to gas analyzers to power meters, displays, controllers, and much more… all of which can now be interrogated by the IntelliLogger equipped with the new Modbus TCP Client option.

Programming the IntelliLogger as a Modbus TCP Client

In the Modbus TCP Client mode, the IntelliLogger is programmed using the powerful and intuitive icon-based programming capability provided by HyperWare-II . A Program Net is built which can query the connected Modbus Server device’s internal registers through the addition of an icon representing that register… much like the method used for logging conventional hardwired input and output signals.

Modbus Server Slave IconA Modbus TCP Server/Slave Device icon is added for each of the Server device registers that the IntelliLogger will access. The values retrieved from the Server device can then be used in further processing within the Program Net just like other analog or digital inputs that have been hardwired to the IntelliLogger (e.g. thermocouples, RTD’s, 4-20mA, voltages, etc).  The received values can be scaled, averaged, used in calculations,  alarms and more.

Additionally, many Modbus Server devices have writable Registers… allowing the IntelliLogger to change settings within the Server device by writing new values into these writable registers. Write functionality may be used for changing alarm thresholds, changing output states, adjusting operational constants, branching of algorithms, input scaling values within the Server device, etc.

Modbus TCP Client Example Net

IntelliLogger Program Net; Sampling the CO concentration from a gas analyzer Server

Modbus Server icons are configured similarly to all HyperWare-II Program Net icons… through the Icon Configuration dialog. Within the Modbus Server icon configuration dialog,  settings such as Server network address (URL and Port), Register address and data format are specified. The icon supports 16 and 32 bit integer, 32 bit floating point and even 16 bit ‘bitfield’ register types. Once the icon for a particular Server device Register is made, it can be quickly tested and optionally saved to the user’s library of Modbus icons for quick future re-use.

Shown is a simple IntelliLogger Program Net sampling the CO concentration from a gas analyzer that has TCP Server capability.  Utilizing the Modbus TCP Client function (Modbus Device icon), every 30 seconds the CO concentration is read from an internal Modbus register in the analyzer and stored to local IntelliLogger memory.  Additionally, the flue gas temperature is sampled every 30 seconds with a hard-wired thermocouple input and the temperature is written to a Modbus TCP register in the analyzer for use in temperature compensation.


Modbus Option Overview

Frequently Asked Questions

  • What capability does the Modbus TCP Client option add to the IntelliLogger?

    • An IntelliLogger with Modbus TCP Client can garner readings from one or more connected Modbus TCP Server device’s memory locations (Registers) that are storing values.  In most cases these Registers contain last readings that a Server device (eg a gas analyzer) just sampled.
  • Can an IntelliLogger be updated with the Modbus TCP Client option in the field?
    • Yes.  As an alternative to sending a deployed IntelliLogger back to Logic Beach for addition of this option, the unit can be upgraded in the field.  Contact Logic Beach with the Model and Serial Number of the field unit and Technical Support can provide a special file that enables this option in the field.  In order to enable the function in the field, a connection between the IntelliLogger and a PC running HyperWare is required (USB, LAN, cell modem, etc).  Due the file preparation costs, there is a nominal charge for the field upgrade in addition to the standard desired Modbus feature to be added.
  • What physical connection is used on the IntelliLogger for the Modbus TCP Client/Server(s) communication?

    • All IntelliLogger models (excluding the IL-Mini) have integral Ethernet communication (Ethernet RJ45 jack).  This connection is used for the Client/Server(s) communications.
  • Can I use the Ethernet port on the IntelliLogger for both connection to a LAN as well as Modbus TCP communications?

    • Yes.  For example, multiple IntelliLoggers,  PC’s and  Modbus TCP Server devices can all be connected on a LAN.  The PC can communicate with the IntelliLogger as normal through HyperWare or a browser.  “Simultaneously”, the IntelliLogger configured as a Modbus TCP Client can be  communicating with the connected Modbus TCP Server devices.  It is even possible to have multiple IntelliLoggers configured as Modbus TCP Clients residing on the same LAN.
  • Can I have an IntelliLogger connected to a cellular gateway (modem) as well as communicating via Modbus TCP with Server devices?

    • Yes, the cellular gateway simply provides the interface between the IntelliLogger and the Internet.  Modbus TCP communication is agnostic relative to the Ethernet connectivity (gateways, switches, hubs, etc).  For example,  an IntelliLogger at a remote location that is connected to the Internet via a cellular gateway could communicate through a firewall into a LAN within a plant  and to a Modbus Server device that is residing on the plant LAN.
    • Additionally, the Ethernet port on the IntelliLogger could be connected to Ethernet switch.  A cellular gateway could be connected to the switch as well as a local LAN.  This would allow for remote communication with the IntelliLogger from a remote office PC via the Internet and gateway at the same time as the IntelliLogger could be garnering register values from Modbus Server devices that are local at the IntelliLogger location.
  • Can an IntelliLogger be performing as a Modbus TCP Client at the same time as using Modbus RTU Master to communicate with Modbus Slave devices?

    • Yes.  The IntelliLogger can be configured for simultaneous operation as a Modbus TCP Client, TCP Server and either Modbus RTU Master or Slave.
  • Can multiple Modbus protocols be implemented in a single IntelliLogger?
    • Yes, as described above but presented a different way,  the following simultaneous options are supported as follows:
      • Simultaneous Modbus RTU Master and Modbus TCP Server and Modbus TCP Client
      • Simultaneous Modbus RTU Slave and Modbus TCP Server and Modbus TCP Client


IntelliLogger Modbus TCP Client Option
Product Name: IntelliLogger Modbus TCP Cllient Option
Order Part Number: MTC Option
Price: $280   (Note that units can be updated in the field with this option for an $80 additional surcharge. Feature updating file will be emailed)
Items included with order:
Product Name:  Part Number: Qty:
Intellilogger Modbus TCP Client Option, software MTC Option  1

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