22-15. Command Structure - Motorola R-2002A Manual

22-15. Command Structure. Each command consists of a two letter definition prefix followed by a numeric
data field. The data field will vary in length and structure according to the definition prefix as shown in table
22-3. Spaces may be inserted anywhere in the command but are not required. Each letter or number of a
command is transferred from the bus controller to thefinalyzer in ASCII format ASCII defines a 7-bit digital
code for each letter, number, and symbol commonly used in computer programming.
22-16. The first letter of the two letter prefix identifies a command category with the second letter identifying
a particular command within that category. A listing of the command categories and the corresponding first
letter is provided in table 22-2. A complete list of commands is shown in table 22-3.
Table 22-2. Command Categories
A
c
F
G
K
M
0
R
v
w
Audio Synthesizer
Control
Frequency Counter
Generate/Monitor Control
Keyboard
Modulation
Oscilliscope
Receiver
Voltmeter
Wattmeter
22-17. The data field is comprised of five sub-fields as shown:
±
n.n
E ±
n
I
DATA SIGN
I
I
EXPONENT
"'
EXPONENT MAGNITUDE
\
DATA VALUE
EXPONENT SIGN
Data limits and accompanying units are given in table 22-3. The data field is optional or not allowed for certain
commands.
22-18. Data Sign. The data sign is a single'+' or'-' character indicating the sign of the data value. The sign
may be omitted for positive value data.
22-19. Data Value. The data value field is restricted to the numbers '0' through '9' and·.·. A maximum of five
digits to the right and to the left of the decimal point are allowed. The decimal point can be omitted for integer
values. If the value field is omitted, it is assumed to be zero.
22-20. Exponent. The presence of the "E" character in the exponent field indicates that the data value is to
be multiplied by 10 raised to the power following the "E" character. If the "E" is omitted the exponent is
assumed to be 10° or 1.
22-21. Exponent Sign. The exponent sign is a single
+
or character and can be omitted for positive
exponent values.
22-22. Exponent Magnitude. The exponent magnitude is a single character 0 through 9. If the exponent
magnitude is omitted, it is assumed to be zero.
22-4