Serial Line Configuration - GMP251 - GMP252

Relay Box for GMP250 Carbon Dioxide Probes Quick Guide

Document code
English (United States)
Document type
User guide

To enable relay operation, you must use a terminal program (for example, PuTTy) to set the GMP251/252 serial mode to relay communication and configure the relay settings. Using serial line (Vaisala Industrial Protocol) to configure the probe requires the following:

  • Vaisala USB service cable (order code 242659)
  • Computer with:
    • Windows operating system
    • Terminal application (for example PuTTy, available from
    • Free USB port
    • Driver for Vaisala USB service cable installed (available on the cable installation media and at

The default serial interface settings are shown in the following table.

Table 1. Default Serial Interface Settings
Property Description/Value
Bit rate 19200
Parity None
Data bits 8
Stop bit 1
Flow control None
For more detailed instructions on connecting to GMP251/GMP252 with a computer and using the serial line interface, see the User Guides of the probes.