More info on the Modbus Protocol

Monico supports thousands of customers by providing data converted to the popular Modbus RTU and Modbus TCP protocols. We have numerous standard, ready to use configuration files making data available over TCP/IP (Ethernet) and serial RTU (RS232 and RS485). Our default Modbus 30K configurations provide data scaled for Imperial and Metric units in 16-bit WORD, 32-bit INTEGER, and 32-BIT FLOAT data types. Flags are parsed out of WORDS and 32-bit INTEGERS and placed into 10K registers for easier incorporation into Remote Monitoring environments.


The Monico Gateway has ports to interface over multiple drops and network types simultaneously including a mix of Modbus and other output protocols. It has 2 RS232 and 1 RS485 (with an optional second port) and Ethernet ports. The Monico Gateway Ethernet can support up to 4 protocols simultaneously. Besides our full selection of pre-configured setup files for customer convenience, our tools allow full creation and customization capabilities by Monico or by the user to fit any installation. Our easy-to-use Monicoview and Monicoview II programming software allows simple adjustment of all communication settings including IP and serial addressing. This software can be downloaded from the Software & Tools section of the Support section of our website. Options include designation of master and slave and Modbus standard data types including read, read/write for:

  • Digital Coils
  • Digital Inputs
  • Analog Inputs
  • Holding Registers
  • File Registers
  • Holding Registers (32-bit)

We have an array of preconfigured files utilizing Modbus for our customers when communicating with Cummins and Kohler equipment. The "default" Monico configuration file is in 30XXX addressing because, as scaled (Imperial or Metric) Analog Inputs, they are Read-Only but standard 40XXX (unscaled) addressing is also available. Please see our Combined Data Maps for CDL and J1939 in the Support section of this website for more information on the Register Mappings.


Some highlights about Modbus:

Originally published in 19791 by Modicon (now Schneider Electric), Modbus was developed as a serial communications protocol between a single Master and Multiple Slave devices. It is most commonly used with Programmable Logic Controllers (PLCs) and remote sensors. It is an open protocol2 and used industrial communications for the Oil & Gas, Power Generation, and anywhere else automation is found or needed. Modus allows communication between as many as 240 devices on the same serial network and is frequently used to connect supervisory units to remote terminal units in control and data acquisition systems (SCADA). The standard is governed by the Modbus Organization3 which has overseen the open usage since transfer from Schneider Electric in April 2004. Serial Modbus communications requires a single Master unit interrogating one or many slaves on the Network. ModbusTCP (Modbus over Ethernet) maintains the same register schema but allows for multiple Masters interrogating one or many slaves on the Ethernet network. For additional reading on Modbus please visit the website.


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