Serial Line Operation; Using The Service Port; Serial Interface Settings; Installing The Driver For The Usb Service Cable - Vaisala HMT120 User Manual

4. Serial Line Operation
4.1 Using the Service Port
The transmitter's motherboard has an 8-pin RJ-45 connector for service use. The service port
uses RS-232 signaling levels. Vaisala offers an optional USB cable (Vaisala order code 219685)
for connecting the transmitter to your computer.
The service port is intended for short-term use such as calibration. For permanent
installation, use the analog output.
Connecting a computer to the service port may cause erroneous analog output
because of a possible ground loop. Use the service port for service only and
disconnect the computer after the service operation.
The cable can also provide operation power to the transmitter, so the wires at the screw
terminals need not to be connected in order to operate the transmitter.
If you have not used the transmitter's USB cable before, install the driver that came with the
cable.
4.2 Serial Interface Settings
Table 5 Default Serial Interface Settings
Property
Bit rate
Parity
Data bits
Stop bits
Flow control
4.3 Installing the Driver for the USB Service Cable
Only Windowsâ operating systems are supported by the driver of the USB
service cable.
1. Connect the USB service cable to a USB port on your computer. Windowsâ detects the
new device and installs the appropriate driver.
Chapter 4 – Serial Line Operation
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