Section Five IBIC©National Instruments Corp. 5-13 GPIB-PC User Manual6. string consists of a list of ASCII characters, octal or hexbytes, or special symbols. The entire sequence of charactersmust be enclosed in quotes. An octal byte consists of abackslash character followed by the octal value. For example,octal 40 would be represented by 040. A hex byte consists of abackslash character and a character x followed by the hexvalue. For example, hex 40 would be represented by x40. Thetwo special symbols are \r for a carriage return character and\n for a linefeed character. These symbols provide a moreconvenient method for inserting the carriage return and linefeedcharacters into the string as shown in this string:"F3R5T1\r\n". Since the carriage return can be representedequally well in hex, \xD and \r are equivalent strings.SET (Select Device or Board)The SET function specifies a previously opened device or board to beused for subsequent GPIB-PC functions executed from IBIC. SETeliminates the need to include the BD unit descriptor in each GPIB-PCfunction call.The argument bdname is any of the symbolic device or board namesrecognized by the handler. These are the default names gpib0,gpib1, and dev1 through dev16 unless the device names have beenchanged with IBCONF.An example of the SET function appeared earlier in this section.HELP (Display Help Information)The HELP function gives causal information about IBIC and itsfunctions to be displayed on the screen.
