Sweep Time Accuracy - HP 8340A Operating Manual

except the Line switch and Set H P-1 B Address. Pro­
gramming data consists of a string of ASCII coded
characters composed of one or more of the follow­
ing control fields:
Sweep Mode/Limits
•
Frequency Markers
•
Sweep Mode, Trigger, and Time
•
Modulation
•
Step Size, Display, and Entry Control
•
Instrument State/Registers
•
Power Level and Control
•
Special HP-I B Only Functions
•
Diagnostic Functions
•
INPUT SYNTAX
The 8340A responds to program codes in the order in
which they are received. Each function is pro­
grammed with a string of ASCII coded characters
that follow one of these sequences:
[Function Code] [Numeric Value]
•
Terminator]
[Function Code]
•
NOTE
The HP-18 program code sequence typi­
cally mirrors that of the local front panel
keystroke sequence.
FUNCT ION CODES (PREFIX ACT IVATE)
Function codes are typically 2 to 4 character
mnemonics. For functions that have a numeric value
associated with them, passing the function code
only will enable and activate the function for further
data entry.
NUMERIC VALUE (NUMERIC FORM AT )
These are either a single decimal digit, a set of 14
characters or less representing a number, or a string
of binary bytes. A string of 14 characters maximum
can be expressed in exponential, decimal·or integer
form. Acceptable numeric formats are referenced in
later sections by the following format syntax:
Format#1: Exponential
Format #2: Decimal.
Format#3: Integer
Format #4: Single Digit
Format#5: Binary String
Format #6: Binary Byte
Where the character 'd' indicates a leading or trail­
ing zero, a space, or a numeric digit
The character 'b' indicates an 8-bit binary byte. The
characters '***' indicate a variable number of the
[Numeric
±d***d.d***dE±dd
± d***d.d***d
±d***d
d
b***b
b
through 9).
(O
Scans by HB9HCA and HB9FSX
previous character. Numeric values that are not bi­
nary in nature are scaled by the appropriate numeric
terminator.
NUMERIC TERM INAT ORS
Numeric terminators are of 2 types, mnemonic and
fundamental terminators. Mnemonic terminators
are 2-character codes that terminate and scale the
associated numeric value. Thus, frequency values
can be entered in GHz (CZ), MHz (MZ), kHz (KZ), or
Hz (HZ); sweep time values can be entered in
seconds (SC) or milliseconds (MS) and power values
can be entered in dB or dBm (both DB). Fundamen­
tal terminators consist of the ASCII characters Line
Feed or Next Line (LF or NL, decimal 10), semicolon
(';', decimal 59), or comma(',', decimal 44), and may
be used in lieu of a mnemonic terminator. However,
when this is done the 8340A assumes the numeric
value is in the fundamental units of Hz, seconds or
dB.
VALID CHARACTERS
The alpha program codes can be either upper or
lower case since the 8340A will accept either type
(they can be interchanged). Spaces, unnecessary
signs ), leading zeroes and carriage returns
( +,
-
(CR) are ignored. Characters containing a parity bit
will have that bit cleared by the 8340A.
PROGRAMM ING DATA
See Table 1 for Input Programming Codes.
If different step attenuator settings exist
between the foreground and background
states of an Alternate Sweep, the 8340A
will perform the Alternate Sweep func­
tion, but the step attenuator will not vary
from the foreground state in order to
avoid excessive attenuator wear.
INS T RUMENT PRESET
Instrument Preset turns off all functions then sets
the following:
Sweep Mode: Start/Stop
Start 10 MHz
=
Stop 26.5 GHz
=
Sweep: Continuous
Trigger: Free Run
Sweep Time
=
band)
Markers: All values set to center of frequency span,
all off
2
NOTE
44.15 ms (minimum for full