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03 Format
The 03 format transmits trace amplitude information only, in measure units: Hz, dBm, dB, volts, or seconds. The
03 format cannot transmit instruction words.
A carriage-return/line-feed (ASCII codes 13, 10) always follows any data output. The end-or-identify state (EOI)
is asserted with line feed.
Instrument preset (IP) automatically selects the 03 format.
01 Format
The 01 format transmits trace amplitude information as decimal values in display units. (See Chapter 4 in Section
I for a description of display units.)
Trace amplitude values can be positive and unblanked, positive and blanked, or negative and blanked. Positive,
unblanked values (fJ to 1023) cover the visible amplitude range on the spectrum analyzer CRT
Negative trace values (3072 to 4095) usually result from trace arithmetic, and are not displayed because they are
off (below) the screen. Negative values are represented by the X&bit two's complement of the negative number,
that is, 4096- (negative valuel. For example, a - 300 values is an output of 3796.
Positive, blanked values (2048 to 3071) are those responses immediately ahead of the updated, sweeping trace.
These values form the blank-ahead marker, and represent the amplitude responses of the previous sweep, plus
2048. Thus, they are off (above) the screen (See Appendix B.)
The 01 format also transmits instruction words as decimal values. See the Instruction and Data Word Summary in
Appendix B.
A carriage-return/line-feed (ASCII codes 13, 10) always follows any data output in the 01 format. The
end-or-identify state (EOI) is asserted with line feed.
02 Format
The 02 format transmits trace information or instruction words as two 8-bit binary numbers. The most significant
bit is sent fii. The four most significant bits are always zeroes.
Most Significant Byte
Refer to the Consolidated Coding table in Appendix B for instruction word information.
Note that the 02 format sends the same kind of information that the 01 format sends, except that 02 transmits
the information in binary numbers instead of decimal numbers. Also, the end of transmission is not marked by
carriage-return/line-feed (ASCII codes 13, 10) in the 02 format.
282 Programming
4096 - I- 3001 = 3796
0000 xxxx
Least Significant Byte
xxxxxxxx
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