Instruction manual

The baud rate is user selectable. However the BOS/S controller requires an 8-bit

word, 1 stop, and 1 start bit for proper communications. There is no hardware

handshaking, a properly received character will be echoed back over the RS232 line

assuming that the echo function is enabled. The default is to echo all characters, this

is modified using the SET BACKTALK COMMAND.

SB1 = echo on SB0 = echo off

6.3 SET UP COMMANDS

There are several commands that may be issued to the BOS/S controller to select

operating conditions.

Each must be followed by CR LF (ASCII 13, ASCII 10).

The set commands are as follows:

“Set Local” = “SL” = local operation (def)

“Set Remote” = “SR” = remote operation

“Set I Control” = “SI” = current control

“Set V Control” = “SV” = voltage control (def)

“Set Backtalk 0” = “SB0” = RS232 echo off

“Set Backtalk 1” = “SB1” = RS232 echo on (def)

“Set Message length 0” = “SM0” = short output

“Set Message length 1” = SM1” - verbose output (def)

These commands may be explicitly spelled out in the command string sent to the

BOS/S controller, but only those letters that are capitalized are actually needed. The

rest are ignored.

e.g. “Set Message 0” is the same as “SM0”

“Set Remote” is the same as “SR”

6.4 INQUIRY COMMANDS

There are several inquiry commands used to check the operating conditions of the

BOS/S. Each commands must have as its first character a question mark (?) or the

letter “I”. Each must be followed by a CR LF (ASCII 13, ASCII 10). Each of these

commands will result in a message being placed in the output buffer. the length of the

returned message is determined by the setting of the BACKTALK bit (see above)

The inquiry commands are as follows:

“? Control” = “?C” = Voltage or current control?

“? Operation” = “?O” = Local or remote operation?

“? Limit +” = “?L+” = +Limit DAC programming value (hex)?

“? Limit –” = “?L–” = –Limit DAC programming value (hex)?

“?M” will put a message in the output buffer of the following form:

“E/M Model BOS/S 20-10-1-D-3-2-PM Serial 90A-1234”

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