Hewlett-Packard 8566B

Hewlett-Packard

8566B

100 Hz to 22 GHz spectrum analyzer

spectrum_analyzer Proprietary

HP 8566B spectrum analyzer with 85662A display — eBay listing photo

Default Address 18

Termination LF

IEEE 488.2 No

IDN Patterns

*,8566B,*,*

Documentation

9018-01297.pdf (original)

The 8566B is a legacy HP-IB (pre-IEEE 488.2) spectrum analyzer produced from the early 1980s through the 1990s. It uses a proprietary command syntax with short mnemonics and unit suffixes rather than SCPI. The instrument does not support *IDN? or other IEEE 488.2 common commands; use the ID? proprietary command for identification. Frequency coverage is 100 Hz to 22 GHz (2.5 GHz with internal mixer, to 22 GHz with external mixing). The trace contains 1001 display points. The 8566B replaced the 8566A with improved amplitude accuracy and additional digital features.

Status Byte

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
Unused	RQS	Command Complete	MAV	End of Sweep	Error	Unused	Unused
Not used	Requesting service	Requested operation completed	Message available in output buffer	Sweep has completed	Command or hardware error	Not used	Not used

Use serial poll to read status byte. SRQ is asserted based on the SRQ mask set with SQUELCH/SRQ commands. This instrument predates IEEE 488.2 so *STB?/*SRE are not available.

Commands

Frequency Control

Set center frequency, start/stop frequencies, and frequency span. Values are specified with a numeric value followed by a unit suffix.

Command	Type	Description
`CF {freq}HZ`	command	Set center frequency in Hz
Details Parameters `freq` (numeric) — Center frequency in Hz (100 to 22e9) Example `CF 1000000000HZ`
`CF {freq}KZ`	command	Set center frequency in kHz
Details Parameters `freq` (numeric) — Center frequency in kHz Example `CF 1000000KZ`
`CF {freq}MZ`	command	Set center frequency in MHz
Details Parameters `freq` (numeric) — Center frequency in MHz Example `CF 1000MZ`
`CF {freq}GZ`	command	Set center frequency in GHz
Details Parameters `freq` (numeric) — Center frequency in GHz Example `CF 1GZ`
`CF?`	query	Query current center frequency
Details Returns (numeric) — Center frequency in Hz Example: `1000000000`
`FA {freq}HZ`	command	Set start frequency in Hz
Details Parameters `freq` (numeric) — Start frequency in Hz Example `FA 900000000HZ`
`FA {freq}MZ`	command	Set start frequency in MHz
Details Parameters `freq` (numeric) — Start frequency in MHz Example `FA 900MZ`
`FA?`	query	Query start frequency
Details Returns (numeric) — Start frequency in Hz Example: `900000000`
`FB {freq}HZ`	command	Set stop frequency in Hz
Details Parameters `freq` (numeric) — Stop frequency in Hz Example `FB 1100000000HZ`
`FB {freq}MZ`	command	Set stop frequency in MHz
Details Parameters `freq` (numeric) — Stop frequency in MHz Example `FB 1100MZ`
`FB?`	query	Query stop frequency
Details Returns (numeric) — Stop frequency in Hz Example: `1100000000`
`SP {span}HZ`	command	Set frequency span in Hz
Details Parameters `span` (numeric) — Span in Hz (0 for zero-span) Example `SP 200000000HZ`
`SP {span}KZ`	command	Set frequency span in kHz
Details Parameters `span` (numeric) — Span in kHz Example `SP 200000KZ`
`SP {span}MZ`	command	Set frequency span in MHz
Details Parameters `span` (numeric) — Span in MHz Example `SP 200MZ`
`SP {span}GZ`	command	Set frequency span in GHz
Details Parameters `span` (numeric) — Span in GHz Example `SP 2GZ`
`SP?`	query	Query current span
Details Returns (numeric) — Span in Hz Example: `200000000`

Amplitude Control

Reference level, attenuation, and amplitude units

Command	Type	Description
`RL {level}DM`	command	Set reference level in dBm
Details Parameters `level` (numeric) — Reference level in dBm (-120 to +30) Example `RL 0DM`
`RL?`	query	Query reference level
Details Returns (numeric) — Reference level in current amplitude units Example: `0.0`
`AT {atten}DB`	command	Set RF input attenuation in dB
Details Parameters `atten` (numeric) — Attenuation in dB (0 to 70, 10 dB steps) Example `AT 10DB`
`AT?`	query	Query input attenuation
Details Returns (numeric) — Attenuation in dB Example: `10`
`AUNITS DBM`	command	Set amplitude units to dBm
`AUNITS DBMV`	command	Set amplitude units to dBmV
`AUNITS DBUV`	command	Set amplitude units to dBuV
`AUNITS VOLT`	command	Set amplitude units to volts
`AUNITS WATT`	command	Set amplitude units to watts
`AUNITS?`	query	Query current amplitude units
Details Returns (string) Example: `DBM`
`LG {scale}DB`	command	Set log scale (dB per division)
Details Parameters `scale` (numeric) — dB per division (1, 2, 5, 10) Example `LG 10DB`
`LN`	command	Switch to linear amplitude scale

Bandwidth Control

Resolution bandwidth and video bandwidth settings

Command	Type	Description
`RB {bw}HZ`	command	Set resolution bandwidth in Hz
Details Parameters `bw` (numeric) — Resolution bandwidth in Hz Example `RB 10000HZ`
`RB {bw}KZ`	command	Set resolution bandwidth in kHz
Details Parameters `bw` (numeric) — Resolution bandwidth in kHz Example `RB 10KZ`
`RB?`	query	Query resolution bandwidth
Details Returns (numeric) — Resolution bandwidth in Hz Example: `10000`
`RB AUTO`	command	Set resolution bandwidth to auto-coupled mode
`VB {bw}HZ`	command	Set video bandwidth in Hz
Details Parameters `bw` (numeric) — Video bandwidth in Hz Example `VB 1000HZ`
`VB {bw}KZ`	command	Set video bandwidth in kHz
Details Parameters `bw` (numeric) — Video bandwidth in kHz Example `VB 1KZ`
`VB?`	query	Query video bandwidth
Details Returns (numeric) — Video bandwidth in Hz Example: `1000`
`VB AUTO`	command	Set video bandwidth to auto-coupled mode

Sweep Control

Sweep time, trigger mode, and single-sweep control

Command	Type	Description
`ST {time}SC`	command	Set sweep time in seconds
Details Parameters `time` (numeric) — Sweep time in seconds Example `ST 1SC`
`ST?`	query	Query sweep time
Details Returns (numeric) — Sweep time in seconds Example: `0.1`
`ST AUTO`	command	Set sweep time to auto-coupled mode
`TS`	command	Take sweep — trigger a single sweep and wait for completion
Details Note: Blocks GPIB until sweep is complete. Use after setting TM SNGL for controlled data acquisition.
`TM FREE`	command	Set trigger mode to free-run (continuous sweep)
`TM SNGL`	command	Set trigger mode to single sweep
`TM LINE`	command	Set trigger mode to line trigger
`TM EXT`	command	Set trigger mode to external trigger
`TM?`	query	Query current trigger mode
Details Returns (string) Example: `FREE`

Marker Control

Marker positioning, peak search, and marker readout

Command	Type	Description
`MKPK HI`	command	Move marker to highest peak on display
`MKPK NH`	command	Move marker to next highest peak
`MKPK NR`	command	Move marker to next peak to the right
`MKPK NL`	command	Move marker to next peak to the left
`MKA?`	query	Query marker amplitude
Details Returns (numeric) — Marker amplitude in current units Example: `-23.5`
`MKF?`	query	Query marker frequency
Details Returns (numeric) — Marker frequency in Hz Example: `1000000000`
`MK {freq}HZ`	command	Position marker at specified frequency in Hz
Details Parameters `freq` (numeric) — Marker frequency in Hz Example `MK 1000000000HZ`
`MK {freq}MZ`	command	Position marker at specified frequency in MHz
Details Parameters `freq` (numeric) — Marker frequency in MHz Example `MK 1000MZ`
`MKCF`	command	Set center frequency to current marker frequency
`MKN`	command	Turn marker to normal mode
`MKD`	command	Activate delta marker (reference to current marker position)
`MKOFF`	command	Turn off all markers
`MKMIN`	command	Move marker to minimum trace point

Trace Control

Trace data readout and trace operations

Command	Type	Description
`TRA?`	query	Query trace A data — returns 1001 comma-separated amplitude values
Details Returns (string) — 1001 amplitude values in current units, comma-separated Example: `-70.5,-68.2,-65.1,...` Note: Returns 1001 data points covering the current span. Each point is an amplitude in the current AUNITS.
`TRB?`	query	Query trace B data — returns 1001 comma-separated amplitude values
Details Returns (string) — 1001 amplitude values in current units, comma-separated
`CLRW TRA`	command	Clear-write trace A (reset to clear and begin new data)
`CLRW TRB`	command	Clear-write trace B
`VAVG {count}`	command	Enable video averaging with specified count
Details Parameters `count` (numeric) — Number of sweeps to average (1 to 999) Example `VAVG 10`
`MXMH TRA`	command	Set trace A to max-hold mode
`VIEW TRA`	command	Set trace A to view mode (freeze trace)
`BLANK TRA`	command	Blank (hide) trace A
`BLANK TRB`	command	Blank (hide) trace B

Instrument Control

General instrument preset, identification, and state control

Command	Type	Description
`IP`	command	Instrument preset — reset all settings to defaults (CF 11.01 GHz, full span, RL 0 dBm, auto-coupled BW and sweep)
`ID?`	query	Query instrument identification
Details Returns (string) — Model identification string Example: `HP8566B`
`CS`	command	Clear status — clears error conditions and status byte
`ERR?`	query	Query error status
Details Returns (numeric) — Error code (0=no error) Example: `0`
`DONE?`	query	Query whether current operation has completed
Details Returns (numeric) — 1=done, 0=not done Example: `1`

Common Workflows

Measure Signal

Measure a known signal by setting center frequency and span, then reading marker amplitude

Preset instrument to known state

IP

Set center frequency to 1 GHz

CF 1000MZ

Set span to 10 MHz

SP 10MZ

Set reference level to 0 dBm

RL 0DM

Set amplitude units to dBm

AUNITS DBM

Set single sweep mode

TM SNGL

Take a sweep

TS

Move marker to peak

MKPK HI

Read marker frequency

MKF?

Expected: Frequency in Hz

Read marker amplitude

MKA?

Expected: Amplitude in dBm

Find Peak

Find the strongest signal across a wide span and zoom in for accurate measurement

Preset instrument

IP

Set wide span for search

SP 2GZ

Set reference level high enough to avoid clipping

RL 10DM

Single sweep

TM SNGL

Take a sweep

TS

Find highest peak

MKPK HI

Center display on peak

MKCF

Narrow span for detail

SP 1MZ

Take another sweep

TS

Find peak again in narrower view

MKPK HI

Read marker frequency

MKF?

Expected: Frequency in Hz

Read marker amplitude

MKA?

Expected: Amplitude in dBm

Set Span and RBW

Configure span and resolution bandwidth for a specific measurement, with video averaging for noise reduction

Preset instrument

IP

Set center frequency

CF 1000MZ

Set span to 100 kHz

SP 100KZ

Set resolution bandwidth to 1 kHz

RB 1KZ

Set video bandwidth to 100 Hz

VB 100HZ

Set reference level

RL -20DM

Enable video averaging for 20 sweeps

VAVG 20

Single sweep mode

TM SNGL

Take a sweep (waits for all averages)

TS

Read trace A data

TRA?

Expected: 1001 comma-separated amplitude values