VSI / VLT FAQ / Resources
General Information
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Q:I can't get the serial baud rate change to work correctly. I believe I'm changing the baud rate on my side correctly, but maybe not. Is 38400 the highest speed possible?
A: The VSI-C2 accepts several commands from the host computer via an RS-232 port. When the VSI-C2 powers up, it defaults to 28.8K baud. All commands consist of at least two ASCII characters and are terminated with an ASCII carriage return. Some commands require additional binary data. All binary data is sent with a 2's compliment check sum value such that when all of the bytes transmitted are added, the result is zero.In the manual: Section 3.11 Set RS232 Baud Rate This command allows the user to change the communications baud rate between the host computer and the VSI-C2. Almost any baud rate is possible, the most common are listed below.
Command Format: B "rate" followed by a carriage Return (CR) Baud rate divisor
8DH = 38.4K baud
91H = 28.8K baud
9AH = 19.2K baud
BDH = 8192 baud
Command Responses:
: Command received ?1: Command not understood ?2: Invalid rate Suggest order of operation on connect to change baud rate.
1. Connect at 28.8K
2. Request 38.4K
3. Verify command understood
4. Reconnect at 38.4K
Note: On power down of the VSI the baud rate will default back to 28.8K.
[REF - 020]
