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Programming
VLT
®
Series 2000
Group 5 -- Serial Data Interface
Using the serial RS 232 port (terminals 71 and 72) you can
read and set parameters of the VLT adjustable frequency
drive and issue reference and control commands. The
serial port can be used for point to point communication
between the VLT and a PC. Communication takes place by
means of a protocol specified by Danfoss, and using the
echo function (parameter 500) you can connect several VLT
adjustable frequency drives.
The data format consists of 10 bits:
One start bit (logical 0)
Eight data bits
One stop bit (logical 1)
Set the baud rate (rate of transmission) in parameter 501
and the address of each unit in parameter 500.
Protocol:
The communication protocol for the VLT Series 2000
consists of 22 ASCII characters make it possible to operate,
set and read parameters, and to receive status feedback
from the VLT adjustable frequency drive.
The communication takes place in the following way:
The master sends a telegram to a VLT adjustable frequency
drive. Then the master awaits a reply from the VLT before
sending a new message. The reply to the master resembles
the telegram sent by the master, but now contains any
updated data values and the status of the VLT.
Data format
Telegram format
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