VLT ® 2000 Series The control possibilities of the VLT I Serial data interface (group 5..) Using the serial RS 232 port (terminals 71 and 72) you can read and set parameters of the VLT frequency converter and issue reference and control commands. The serial port can be used for point-to-point commu- nication between the VLT frequency converter and a PC. Communication takes place by means of a protocol specified by Danfoss, and using the echo function (para. 500) you can connect several VLT frequency converters. Protocol: The communication protocol for the VLT 2000 Series consists of 22 ASCII characters.
These characters make it possible to operate, set and read parameters, and to receive status feedback from the VLT frequency converter. The communication takes place in the following way: The master sends a telegram to a VLT frequency converter. Then the master awaits a reply from the frequency converter 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 frequency converter. The data format consists of 10 bits: One start bit (logical 0) Eight data bits One stop bit (logical1) Set the baud rate (rate of transmission) in parameter 501 and the address of each unit in parameter 500.
Data format Telegram format 54 MG.20.B6.02 – VLT is a registered Danfoss trademark