Connecting to serial interface - HMP110 - HMP113 - HMP60 - HMP63

HMP60 and HMP110 Series User Guide

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User guide

Connection to the serial interface is through the 4-pin connector on the probe.

For temporary use of the serial interface (for example, calibration), you can use the optional Vaisala USB cable (item code 219690). Before you can use the cable, you must install the provided USB driver on your PC.

The Vaisala USB cable is not designed for permanent installations. When using the USB cable, no separate power unit is needed. The probe is powered through the USB port.

For permanent interfacing to a host system, use a shielded cable with a threaded connector.

The probe does not echo typed characters back to the terminal screen. To see the commands you type, you need to enable the "local echo" setting in your terminal program.

A new command cannot be received while the probe is sending data out. Wait until the instrument has completed its response before entering the next command.

Table 1. Default serial communication settings
Property Description/Value
Baud rate 19200
Parity None
Data bits 8
Stop bits 1
Flow control None

You can change the serial settings and operate in RUN, STOP, POLL, and MODBUS modes.

After power-up the probe (in STOP mode) outputs the software version and the command prompt.

  • In RUN mode, a measurement output starts immediately after power-up.
  • In POLL mode, the probe does not output anything after power-up. It must be accessed with an addressed command.
  • In MODBUS mode, the probe does not output anything after power-up: serial line commands are not in use and the probe must be used with the Modbus protocol.