Direct NT3S Connection Using Modbus

This tutorial is intended as an overview of direct NT3S Connection using Modbus.

Components used:
• EJ1N-TC__-__
• 24 Volt Supply
• NT3S-121/3B
• E58-CIFQ1 for configuration of CelciuXº
  • Connect to CelciuXº with CX-Thermo and set Port B of all of the connected modules to Modbus communication 8 databits, No Parity, 1 Stop bit, 115.2kBaud.
  • Use the following wiring to connect to COM1 of NT3S:
    1,4 (9 Pin male)  6 EDU; 8,9 (9 Pin male)  7 EDU
    Use a 110Ω to 125 Ω 1/2W terminating resistor
  • With NTXS set the following for setup of the communications port

  • Create Tags referring to appropriate addresses of the CelciuXº units

    Creating tags

    Note that the address of parameters should be set to the Modbus address in decimal (it is specified in HEX in the manual) plus 1 with Holding registers. For example, pv1 which is address H0200 will be Holding registers 513 or 400513. The address for operation commands is 465536. All read and write parameters are done in 1-Word (2 byte) format.
  • Write a screen application of the type

    Display Data is used for parameters like PV; Data Entry is used for parameters like setpoint. Operation commands can be done by writing a simple task behind a button.

  • Download the application and firmware to NT3S
  • HMI can now be used for commissioning, operation and maintenance of the instruments.