Vaisala AQT400, User Manual

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RS-232 Serial Interface
The RS-232 interface is used to control AQT400 either with a command line interface or with
AQT Configuration Tool. Use the following settings:
• 115200 bps
• 8N1 (8 data bits, no parity, one stop bit)
• no flow control (disable with the command line interface)
RS-485 Serial Interface
The RS-485 interface is used to control AQT400 either with a command line interface or
with AQT Configuration Tool. RS-485 interface uses the following default settings:
• 4800 ... 115200 bps (default value is 9600 bps)
• 7E1 (7 data bits, even parity, one stop bit)
• 120 Ω termination
Change the serial interface and protocol settings through a control connection. The interface
supports the following data transfer protocols: Modbus ASCII and ASCII formatted text with
comma separated values.
When using the RS-485 interface, use a protected and twisted pair cable with both ends
terminated with a 120 ohm termination resistor. AQT400 has been terminated by default.
To remove the termination, contact Vaisala technical support.
4.6. Switching on Power Supply
Verify that AQT400 is properly connected to a power source and any other systems. Switch
on the power supply.
Chapter 4 – Installation
15