4.3811.00.000_US-Anemometer-DSP_eng.doc
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7 Functional
Description
The functioning of the ULTRASONIC anemometer is described below. Due to the internal structure
certain functions depend on other functions. Such dependency is described in each case. For
example, in half duplex mode independent telegram output is not permissible. There are also
restrictions regarding the functional definition of the cable connector. This is due to the double
assignment of individual PINs.
7.1 Serial
communication
The ULTRASONIC provides an RS485 interface for serial communication. It can be operated either
in full or half duplex mode and at different baud rates.
A standard terminal program is used for communication with the ULTRASONIC. With a Windows-
based operating system Hyper Terminal is included in the scope of supply.
It has to be subsequently installed if required.
The ULTRASONIC does not contain any pull-up or pull-down resistors or a wave terminating
resistor.
When starting the ULTRASONIC, the communications parameters are output to the serial interface.
Output takes place at 9600.8N1. The baud rate, the duplex modus and the ID are output:
Example:
THIES ULTRASONIC
!00BR00006
!00DM00000
The ULTRASONIC starts with ID 0, a baud rate of 19200.8N1 and half duplex mode.
