Getting Started with Profibus DP Modules

This document provides basic information about the Profibus DP interface for the Q.bloxx Classic and Q.series X modules.

In order to communicate directly with Profibus DP to the Q.bloxx Classic or Q.series X modules, the modules need to be supplied with dedicated firmware. Please contact your local Gantner Instruments representative for further assistance.


Module Configuration

In order to link the Profibus DP modules to a PC, a USB-to-RS485 converter is necessary.

Wiring of Profibus DP

❗The A- and B-pins on the RS485 interface of the Q.bloxx Classic and Q.series X modules are not equivalent to the Profibus A- and B-lines.

  • A (master) → B (module)
  • B (master) → A (module)


GSD file

GSD files contain essential information regarding a module's capabilities. With a GSD file, system integrators can ascertain fundamental details such as communication options and available diagnostics. These files adhere to a standardized format outlined in the Profibus guidelines. The GSD files for modules are typically located in the ICP 100 program directory (C:\Users\Public\Documents\Gantner Instruments\ICP100\GSD), or they can be downloaded from the Gantner Instruments website:

Diagnostic Data

Diagnostic data must be requested by the Profibus master. With the GSD file, the Profibus master can decode a status or error message. The transferred data (8 bytes) is structured as follows:

byte 1

byte 2

byte 3

byte 4

byte 5

byte 6

byte 7

byte 8











The corresponding part of the GSD file is:

Unit_Diag_Bit(16) = "Underrange Input 1"
Unit_Diag_Bit(17) = "Overrange Input 1"
Unit_Diag_Bit(18) = "Underrange Input 2"
Unit_Diag_Bit(19) = "Overrange Input 2"
Unit_Diag_Bit(20) = "Underrange Input 3"
Unit_Diag_Bit(21) = "Overrange Input 3"
Unit_Diag_Bit(22) = "Underrange Input 4"
Unit_Diag_Bit(23) = "Overrange Input 4"
Unit_Diag_Bit(24) = "Underrange Input 5"
Unit_Diag_Bit(25) = "Overrange Input 5"
Unit_Diag_Bit(26) = "Underrange Input 6"
Unit_Diag_Bit(27) = "Overrange Input 6"
Unit_Diag_Bit(28) = "Underrange Input 7"
Unit_Diag_Bit(29) = "Overrange Input 7"
Unit_Diag_Bit(30) = "Underrange Input 8"
Unit_Diag_Bit(31) = "Overrange Input 8"
Unit_Diag_Bit(32) = "Underrange Output 1"
Unit_Diag_Bit(33) = "Overrange Output 1"
Unit_Diag_Bit(34) = "Underrange Output 2"
Unit_Diag_Bit(35) = "Overrange Output 2"
Unit_Diag_Bit(36) = "Underrange Output 3"
Unit_Diag_Bit(37) = "Overrange Output 3"
Unit_Diag_Bit(38) = "Underrange Output 4"
Unit_Diag_Bit(39) = "Overrange Output 4"
Unit_Diag_Bit(48) = "socket failure"
Unit_Diag_Bit(49) = "Addr from dipp switch"
Unit_Diag_Bit(50) = "Config from Socket"
Unit_Diag_Bit(52) = "not used with Profibus"