grifo® ModBUS Telecontrol

Field serial BUS for grifo® cards

GMT English Tech. Manual PDF format.

Ver. 5.00 - Rel. 23 January 2006.

DEMO GMT program DownLoad

This program runs the whole I/O functions the user needs for Telecontrol operations. G M T manual is under PDF format and it includes the user manual too.


GMT (grifo® ModBUS Telecontrol) is a "Complete Logic Protocol for Serial Communication" developed for the wide range of grifo® industrial cards.

This protocol is based on the famous ModBUS standard that, thanks to its world wide diffusion, ensures the employment either in old and new applications.
The GMT package is the result of numerous experiences, collected in many years, during the development of applications in the industrial environments. In this field the informations must be exchanged between intelligent systems through simple and cheap connections.

In general the ModBUS is a logic protocol that defines the communication rules, in fact it standardizes:

  • the format of communicated messages
  • the modalities of serial line holding and release
  • the identification of devices on the network
  • the number and type of executable commands
  • the data encoding tecnique inside the messages
  • the addressing of hardware resources on the devices
  • the modalities used to check the right communication of messages
  • the handling of errors
  • etc.
  • but it doesn't specify the electric and physic protocol. So the user can freely select, for example, the desidered Baud Rates, the electric driver used for connecction, and so on, to better satisfy its own requirements or to easily fit the features of a communication already developed.

    This documentation assumes that the user already knows ModBUS and so this protocol is not here described. For those users that want a deeper knowledge it is suggested to examine the considerable information available on Internet, or to connect at the following Link:

    The use of GMT deletes, or at least reduces considerably, the development time of a telecontrol application. Normally the long list of high level commands and the complete groups of addressable hardware resources is sufficient for the standard demands. If the application needs additional commands or resources, they can be directly required to grifo®.

    One of the most important features of GMT is that it is a ready to use product: the user is not forced to know the used communication protocol. Thanks to the Utility programs and the libraries provided with the product, it is possible to set up, test and use the communication network in few minutes.
    When the Master system inside the the telecontrol network is a PC, it can be used the numerous programs that already manages the ModBUS protocol, as the SCADA; the software development tools VisualBasic; Visual C; Delphi; etc.

    The GMT package is composed by software on CD, a user documentation and a specific firmware saved on the selected card.


    The most important features of GMT are below summarized:


    - At least one GMT remote device.
    - A Master system, capable to communicate with ModBUS ASCII, through a serial line equal to those available on remote device.
    - Serial cable.


    The use of GMT in conjunction with its commands and the remote devices resources, allows to perform the following functions:

  • Various:
    - read identificatio code of the device;
    - read firmware version;
    - read, write device address;
    - read, write delay for the answer;
    - read, write parity;
    - read, write stop bits;
    - etc.
  • Digital Inputs Outputs:
    - enable, disable single ouput;
    - enable, disable group of ouputs;
    - acquire output status;
    - acquire single input;
    - acquire group of inputs;
    - etc.
  • Analog Inputs Outputs:
    - acquire A/D converter line/s
    - set D/A converter line/s;
    - etc.
  • Counters:
    - set counter/s;
    - acquire counter/s;
    - etc.
  • PWM:
    - set duty cycle of signal/s;
    - acquire duty cycle of signal/s;
    - etc.
  • Memories:
    - read, write EEPROM;
    - read, write backed SRAM;
    - etc.
  • Real Time Clock:
    - Set current date and time data (seconds, minutes, hours, day, month, year, week day);
    - Acquire current date and time data (seconds, minutes, hours, day, month, year, week day);
    - etc.
  • For further information please refer to proper GMT user's manual.

    GMT 518

    grifo® ModBUS Telecontrol with GMM 518


    GMT GM1

    grifo® ModBUS Telecontrol with CAN GM1


    GMT H844-518

    grifo® ModBUS Telecontrol H844 with GMM 518



    grifo® ModBUS Telecontrol with GMM ACB


    grifo® ModBUS Telecontrol with GMM ACB

    GMT HGM1

    grifo® ModBUS Telecontrol with CAN GM1

    House Automation Example. Connection of Sensors and Actuators.

    Last Up-dated at Janury 07, 2012

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