ADCMT 7352A Digital Multimeter Controller

Dual-channel measurement GUI for the ADCMT 7352A 5.5-digit multimeter with OpenGL plotting, independent per-channel settings, and real-time statistics/export.

The communication backend has been written based on the ADCMT 7352A OPERATION MANUAL.

The device is initially detected under Linux as usbtmc. I had to blacklist this kernel module from loading to work with PyVISA.

cat /etc/modprobe.d/usbtmc-blacklist.conf

blacklist usbtmc

I also had to add a udev rule to enable userspace access to the USB device through the dialout group in which my user is added.

cat /etc/udev/rules.d/99-dmm.rules

SUBSYSTEM=="usb", ATTR{idVendor}=="1334", ATTR{idProduct}=="0208", MODE="0666", GROUP="dialout"

Features

• VISA backend/mock for testing — USB via PyVISA (--real)
• Dual-channel acquisition — both A and B channels simultaneously
• Dual Y-axis OpenGL plot
• Per-channel independent function, range, rate, digits, auto-zero, and enable
• Real-time statistics — min, max, avg, stddev, pk-pk, count per channel
• CSV / TXT export with optional timestamp
• Console tab — command entry with autocomplete and history
• Dark / Light theme toggle (persisted across sessions)

Requirements

• Python 3.8+
• PyQt5
• NumPy
• PyOpenGL
• PyVISA - for real hardware, pyvisa-py (optional, USB without NI-VISA)

Quick Start

# Mock mode (no hardware required) — default
python main.py

# Real hardware via USB
python main.py --real

Default VISA resource: USB0::4916::520::999991006::0::INSTR

Command-Line Arguments

Argument	Description
--mock	Use mock backend (no hardware required)
--real	Use real VISA hardware

If neither flag is given, mock mode is used.

Architecture

gui/
├── commands/
│   ├── adc_commands.py   # ADC command registry (F1–F50, ranges, rates, etc.)
│   └── parser.py         # Single/dual response parser, output formatter
├── instruments/
│   ├── adcmt7352a_adc.py # Unified driver (VISA + mock)
│   ├── visa_backend.py   # Real PyVISA backend
│   └── mock_backend.py   # Simulated dual-channel instrument
├── core/
│   ├── config.py         # QSettings persistence
│   ├── theme.py          # Dynamic color scheme per theme
│   ├── worker.py         # Dual-channel acquisition worker (QThread)
│   └── logger.py         # Console log handler
├── ui/
│   ├── main_window.py    # Main window with 3-pane layout
│   ├── panels/           # (reserved for future panels)
│   └── tabs/
│       ├── stats_tab.py  # Real-time statistics
│       ├── export_tab.py # CSV/TXT logging
│       └── console_tab.py# Command console with autocomplete
├── plotting/
│   └── gl_plot.py        # Dual Y-axis OpenGL plot widget
├── resources/
│   ├── styles.qss        # Dark theme stylesheet
│   └── light.qss         # Light theme stylesheet
└── main.py               # Entry point

Initialization Sequence (ADC Mode)

The device can use SCPI commands and special set of ADC Mode commands. Both are described in the documentation. Below is an example of ADC commands used to initialize the device.

*RST   →  H1  →  DE0  →  SD1  →  TRS0  →  INIC1

Step	Command	Purpose
1	*RST	Factory reset
2	H1	Output header ON
3	DE0	Second display OFF (single channel init)
4	SD1	Output first display only
5	TRS0	Trigger source = IMMEDIATE
6	INIC1	Continuous measurement ON

For dual-channel the sequence adds DE1 + SD0 before acquisition.

ADC Command Reference

This section documents all ADC-mode commands. The instrument uses ADC Corporation's proprietary command set (selectable via LANG ADC in the I/F menu).

General rules:

• Commands are ASCII, terminated with \r\n
• After a query command, wait ≥20 ms before reading (USB)
• DSP1,<cmd> applies to the first display (left, default = Ch A)
• DSP2,<cmd> applies to the second display (right, Ch B)
• Omitting the DSP prefix targets the currently selected display (Ch A by default)

Measurement Function Selection

Command	Function	Symbol	Unit	Ch A	Ch B
F1	DC Voltage	DCV	V	✓	—
F2	AC Voltage	ACV	V	✓	—
F3	2-Wire Resistance	2WΩ	Ω	✓	—
F5	DC Current	DCI	A	✓	—
F6	AC Current	ACI	A	✓	—
F7	AC+DC Voltage	ADV	V	✓	—
F8	AC+DC Current	ADI	A	✓	—
F12	DC Voltage (Bch)	BDV	V	—	✓
F13	Diode	DOD	V	✓	—
F20	Low-Power 2WΩ	R2L	Ω	✓	—
F22	Continuity	RCT	Ω	✓	—
F35	DC Current (Bch)	BDI	A	—	✓
F36	AC Current (Bch)	BAI	A	—	✓
F37	AC+DC Current (Bch)	BCI	A	—	✓
F40	Temperature	TC_	°C	✓	—
F50	Frequency	FRQ	Hz	✓	—

Examples:

F1              # Set current display to DCV (Ach)
DSP1,F5         # Set display 1 to DCI (Ach)
DSP2,F12        # Set display 2 to DCV (Bch)
F?              # Query current function (reply: F01..F50)

Function key list per channel:

Channel	Keys
A	F1, F2, F7, F3, F20, F5, F6, F8, F50, F13, F22, F40
B	F12, F35, F36, F37

Range Selection

Ach Ranges

Range Cmd	DCV	ACV/ADV	DCI	ACI/ADI	2WΩ	LP-2WΩ	FREQ
R0	AUTO	AUTO	AUTO	AUTO	AUTO	AUTO	AUTO
R1	—	—	2000 nA	—	—	—	—
R2	—	—	20 µA	—	—	—	—
R3	200 mV	200 mV	200 µA	200 µA	200 Ω	200 Ω	(200 mV)
R4	2 V	2 V	2 mA	2 mA	2 kΩ	2 kΩ	(2 V)
R5	20 V	20 V	20 mA	20 mA	20 kΩ	20 kΩ	(20 V)
R6	200 V	200 V	200 mA	200 mA	200 kΩ	200 kΩ	(200 V)
R7	1000 V	700 V	2000 mA	2000 mA	2 MΩ	2 MΩ	(700 V)
R8	—	—	—	—	20 MΩ	20 MΩ	—
R9	—	—	—	—	200 MΩ	—	—

Bch Ranges

Range Cmd	DCV-Bch (F12)	DCI-Bch (F35)	ACI-Bch (F36)	ACI+DC-Bch (F37)
R0	AUTO	—	—	—
R3	200 mV	—	—	—
R4	2 V	—	—	—
R5	20 V	—	—	—
R6	200 V	—	—	—
R8	—	10 A	10 A	10 A

Examples:

R4              # Manual range 2 V (Ach DCV)
DSP2,R8         # Set Bch range to 10 A
RX              # Switch from AUTO to MANUAL range
R?              # Query range (reply: R0..R9)

Sampling Rate

Command	Rate
PR1	FAST
PR2	MED
PR3	SLOW1
PR4	SLOW2 (same as SLOW1 for frequency)

PR2             # MED rate
PR?             # Query rate (reply: PR1..PR4)

Display Digits

Command	Digits
RE3	3½
RE4	4½
RE5	5½

RE5             # 5½ digit display
RE?             # Query digits (reply: RE3..RE5)

Auto-Zero

Command	Mode
AZ0	OFF
AZ1	ON
AZ2	ONCE (then reverts to OFF)

AZ1             # Auto-zero ON
AZ?             # Query (reply: AZ0 or AZ1)

Continuity Threshold & Temperature Sensor

Command	Description
KOM<n>	Continuity threshold constant, n = 1–1000 Ω (default: 10)
KOM?	Reply: KOMdddd
TCR0	K-type thermocouple
TCR1	T-type thermocouple
TCR?	Reply: TCR0 or TCR1

Trigger System

Command	Description
*TRG	Generate trigger (BUS source)
INI	Exit IDLE state → trigger wait
INIC0	CONTINUOUS OFF
INIC1	CONTINUOUS ON
ABO	Abort measurement → IDLE
TRS0	Trigger source = IMMEDIATE
TRS1	Trigger source = MANUAL
TRS2	Trigger source = EXTERNAL
TRS3	Trigger source = BUS
TRS?	Reply: TRS0–TRS3
TRD<n>	Trigger delay, n = 0–3600 s (default: 0). DSP2 valid when TDE1
TRD?	Reply: TRD±d.ddddE±dd
TDE0	Individual trigger delay OFF
TDE1	Individual trigger delay ON
TDE?	Reply: TDE0/TDE1
TRN<n>	Trigger count, n = 1–50000 (default: 1)
TRN?	Reply: TRNddddd
SPN<n>	Sampling count per trigger, n = 1–16000 (default: 1)
SPN?	Reply: SPNddddd

Typical free-run acquisition:

TRS0            # IMMEDIATE trigger
INIC1           # CONTINUOUS ON

Single-shot with BUS trigger:

TRS3            # BUS trigger
SPN10           # 10 samples per trigger
INIC1           # CONTINUOUS ON
*TRG            # Trigger

Measurement Data Memory

Command	Description
ST0	Memory store OFF
ST1	Memory store ON
ST?	Reply: ST0/ST1
IRD<n>,<m>	Set recall range. Single: 0–19999, Dual: 0–9999
IRO?	Read stored data (see §6.6.2 format)
IRPO?	Read stored data count. Reply: IRPOddddd
IRNO?	Read stored data range. Reply: IRNO ddddd, ddddd
ICL	Clear measurement data memory
MD?	Measured data output request (RS-232 only)

Display & Output Control

Command	Description
DE0	Second display OFF
DE1	Second display ON (dual mode)
DE?	Reply: DE0/DE1
DSP1	Select first display (as target for subsequent commands)
DSP2	Select second display
SD0	Output both displays (comma-separated)
SD1	Output first display only
SD2	Output second display only
SD?	Reply: SD0–SD2
DS0	Measurement data display OFF
DS1	Measurement data display ON
DS?	Reply: DS0/DS1
H0	Header OFF
H1	Header ON
H?	Reply: H0/H1
ODE<n>	Output data element (0 = none, bitmask for calc outputs). n: 0–7
ODE?	Reply: ODEddd
DL0	Block delimiter = CR/LF+EOI
DL1	Block delimiter = LF
DL2	Block delimiter = EOI
DL?	Reply: DL0–DL2
LF?	Power line frequency. Reply: LF0 (50 Hz) or LF1 (60 Hz)

Buzzer & SRQ

Command	Description
BZ0	Buzzer OFF
BZ1	Buzzer ON (default)
BZ2–BZ4	On specific key events (front panel only)
BZ?	Reply: BZ0/BZ1
BP0	Comparator result buzzer OFF
BP1	Buzzer on comparator FAIL
BP2	Buzzer on comparator PASS
BP?	Reply: BP0–BP2
S0	SRQ transmission OFF
S1	SRQ transmission ON
S?	Reply: S0/S1

Calculation Commands

NULL Calculation

Command	Description
NL0	NULL calculation OFF
NL1	NULL calculation ON
NL?	Reply: NL0/NL1
KNL<n>	NULL constant, n = ±999999E+6, resolution 0.00001E-9
KNL?	Reply: KNL±d.dddddE±dd

Smoothing Calculation

Command	Description
SM0	Smoothing OFF
SM1	Smoothing ON
SM?	Reply: SM0/SM1
TI<n>	Smoothing count, n = 2–100 (default: 10)
TI?	Reply: TIddd

Scaling Calculation

Command	Description
SC0	Scaling OFF
SC1	Scaling ON
SC?	Reply: SC0/SC1
KA<n>	Constant A (cannot be zero), n = ±999999E+6 (default: 1)
KB<n>	Constant B, n = ±999999E+6 (default: 0)
KC<n>	Constant C, n = ±999999E+6 (default: 1)
KAM	Set constant A = current measurement value
KBM	Set constant B = current measurement value
KCM	Set constant C = current measurement value
KA?	Reply: KA±d.dddddE±dd
KB?	Reply: KB±d.dddddE±dd
KC?	Reply: KC±d.dddddE±dd

dB/dBm Calculation

Command	Description
DB0	dB/dBm calculation OFF
DB1	dB calculation ON (voltage/current functions only)
DB2	dBm calculation ON (voltage functions only)
DB?	Reply: DB0–DB2
KD<n>	Constant D, n = 0.00001E-9 to 999999E+6 (default: 1)
KDM	Set constant D = current measurement value
KD?	Reply: KD±d.dddddE±dd

MAX/MIN Calculation

Command	Description
MN0	MAX/MIN calculation OFF
MN1	MAX/MIN calculation ON
MN?	Reply: MN0/MN1
MAX?	Read MAX value. Reply: M ±d.dddddE±dd
MIN?	Read MIN value. Reply: I ±d.dddddE±dd
AVE?	Read AVE value. Reply: A ±d.dddddE±dd
AVN?	Read measurement count. Reply: AVN±d.dddddE±dd

Comparator Calculation

Command	Description
CO0	Comparator OFF
CO1	Comparator ON (also sets single measurement)
CO?	Reply: CO0/CO1
HI<n>	HIGH limit constant, n = ±999999E+6 (default: 0)
LO<n>	LOW limit constant, n = ±999999E+6 (default: 0)
HIM	Set HI = current measurement value
LOM	Set LO = current measurement value
HI?	Reply: HI±d.dddddE±dd
LO?	Reply: LO±d.dddddE±dd
LOP0	LOW not specified as PASS condition
LOP1	LOW specified as PASS condition
MIP0	GO not specified as PASS condition
MIP1	GO specified as PASS condition
HIP0	HI not specified as PASS condition
HIP1	HI specified as PASS condition

Statistical Calculation (Memory-based)

Command	Description
SIRD<n>,<m>	Set statistical range & compute. Single: 0–19999, Dual: 0–9999
SIRD?	Read range. Reply: SIRDdddd,dddd
SCNT?	Sample count. Reply: SCNT±d.dddddE±dd
SMAX?	Maximum value in memory. Reply: SMAX±d.dddddE±dd
SMIN?	Minimum value in memory. Reply: SMIN±d.dddddE±dd
SAVE?	Average value in memory. Reply: SAVE±d.dddddE±dd
SSIG?	Standard deviation. Reply: SSIG±d.dddddE±dd (or +9.99999E+11 if ≤1 sample)
SPTP?	Peak-to-peak (MAX-MIN). Reply: SPTP±d.dddddE±dd

Calculation Between 2 Measurements (Dual Math)

Command	Description
MCL0	OFF
MCL1	Display 1 + Display 2
MCL2	Display 1 − Display 2
MCL3	Display 1 × Display 2
MCL4	Display 1 ÷ Display 2
MCL?	Reply: MCLd

Valid only when 2nd display is ON (DE1).

System Commands

Device Control

Command	Description
*RST	Parameter initialization (factory defaults)
*CLS	Clear status registers
*IDN?	Query identity. Reply: ADC Corp.,7352x,<serial>,<rev>
*OPC	Set OPC bit after all operations complete
*OPC?	Reply: 1 after all operations complete
*WAI	Wait for completion (GPIB only)
*TST?	Self-test. Reply: 0 = pass, 1 = fail
*TRG	Bus trigger

Status Registers

Command	Description
*STB?	Read Status Byte Register. Reply: ddd
*SRE<n>	Set Service Request Enable Register, n = 0–255 (bit6 cannot set)
*SRE?	Reply: ddd
*ESR?	Read Standard Event Status Register. Reply: ddd
*ESE<n>	Set Standard Event Status Enable Register, n = 0–255
*ESE?	Reply: ddd
MSR?	Read Measurement Event Register (MER). Reply: ddddd
MSE<n>	Set Measurement Event Enable Register (MEER), n = 0–65535
MSE?	Reply: ddddd
QSR?	Read Questionable Event Register (QER). Reply: ddddd
QSE<n>	Set Questionable Event Enable Register (QEER), n = 0–65535
QSE?	Reply: ddddd
OSR?	Read Operation Event Register (OER). Reply: ddddd
OSE<n>	Set Operation Event Enable Register (OEER), n = 0–65535
OSE?	Reply: ddddd
*PSC<n>	Power-on status clear flag. n ≠ 0 → clear SRER/SESER on power-up
*PSC?	Reply: 0 or 1
*OPT?	Option info. Reply: 0 = no option
ERR?	Read error queue (FIFO, up to 20). Reply: ±ddd,"<message>"

Status Register Structure (PDF §6.6.5)

STB (Status Byte Register):
  bit0: MSB (Measurement Summary)
  bit2: EAV (Error Available)
  bit3: QSB (Questionable Summary)
  bit4: MAV (Message Available)
  bit5: ESB (Standard Event Status)
  bit6: MSS/RQS (Master Summary / Request Service)
  bit7: OSB (Operation Summary)

ESR (Standard Event Status Register):
  bit0: OPC (Operation Complete)
  bit3: DDE (Device Dependent Error)
  bit4: EXE (Execution Error)
  bit5: CME (Command Error)
  bit7: PON (Power On)

MER (Measurement Event Register):
  bit0: FAIL (comparator FAIL)
  bit1: PASS (comparator PASS)
  bit8: EOM (End of Measure)
  bit9: EOS (End of Store)
  bit10: SM (Smoothing Complete)
  bit11: STAT (Statistics Complete)

QER (Questionable Event Register):
  bit0: Voltage Overload
  bit1: Current Overload
  bit4: Temperature Overload
  bit5: Frequency Overload
  bit8: Calibration Summary
  bit9: Ohms Overload
  bit12: Alarm

OER (Operation Event Register):
  bit5: Waiting for TRIG
  bit9: Idle

Save/Recall

Command	Description
*SAV0–*SAV3	Save settings to non-volatile memory area 0–3
*RCL0–*RCL3	Recall settings from area 0–3
SINI	Reset all saved areas to factory defaults
RINI	Load factory defaults as current settings

Calibration

Command	Description
CAL0	Calibration mode OFF (writes calibration factor on exit)
CAL1	Calibration mode ON
CAL?	Reply: CAL0/CAL1
XOUT	Cancel calibration mode (no write)
PC<n>	Enter STD value as displayed count, n = 0–±999999
XDT<n>	Enter STD value as displayed value
CMNT"<str>"	Store calibration info string, up to 50 chars
CMNT?	Reply: CMNT"xxxxxxx"

Function Inhibit

Command	Description
INH<n>,<m>	Set function inhibition. n = function number (1=DCV..50=FREQ), m = 0 (disable) / 1 (enable)
INH?<n>	Query inhibition state for function n. Reply: 0 (disabled) / 1 (enabled)

Output Data Format

Single Display (SD1 / SD2)

With header (H1):

DCV_ +3.29860E+00\r\n

Without header (H0):

+3.29860E+00\r\n

Dual Display (SD0)

With header:

DCV_ +3.29860E+00, BDI_ +1.02400E-01\r\n

Without header:

+3.29860E+00,+1.02400E-01\r\n

Header Codes

Header	Function
DCV	DC Voltage (Ach)
ACV	AC Voltage (Ach)
ADV	AC+DC Voltage (Ach)
R2W	2-Wire Resistance (Ach)
DCI	DC Current (Ach)
ACI	AC Current (Ach)
ADI	AC+DC Current (Ach)
DOD	Diode (Ach)
R2L	Low-Power 2WΩ (Ach)
RCT	Continuity (Ach)
FRQ	Frequency (Ach)
TC_	Temperature
BDV	DC Voltage (Bch)
BDI	DC Current (Bch)
BAI	AC Current (Bch)
BCI	AC+DC Current (Bch)

Sub-Header Codes

Code	Meaning	Priority
_	Normal	8 (lowest)
O	Overload	1
E	Calculation error	2
H	Comparator HI	3
P	Comparator PASS (GO)	3
L	Comparator LOW	3
D	CALC2 (between 2 meas.)	3
M	MAX data	4
I	MIN data	4
A	AVE data	4
B	dB data	5
W	dBm data	6
S	Scaling data	7
N	NULL data	8

Overload & Error Values

Value	Meaning
±9.99999E+37	Overload (OL)
±9.99999E+36	Scaling / CALC2 overflow
±9.99999E+35	dB/dBm error or zero-division in CALC2

The overload threshold (checked by the parser) is 9.9e+36 — any value ≥ this is flagged as overload.

Per-Range Mantissa Formats (Ach DCV example)

Range	Format
200 mV	±ddd.dddE-03
2 V	±dddd.ddE-03
20 V	±dd.ddddE+00
200 V	±ddd.dddE+00
1000 V	±dddd.ddE+00

Full per-range format tables are in the manual (§6.6.2, pp. 6-16–6-17).

Dual Display Operation

The 7352A has two independent AD converters — measurement on both channels is truly simultaneous.

Enabling Dual Display

DE1             # Enable second display (Bch)
DSP1,F1         # Ch A → DCV
DSP2,F12        # Ch B → DCV
SD0             # Output comma-separated dual data

Independent Settings

Each channel has its own function, range, rate, digits, and auto-zero — set using the DSP1,/DSP2, prefix:

DSP1,F1         # Ch A = DCV
DSP1,R4         # Ch A = 2 V range
DSP1,PR1        # Ch A = FAST
DSP1,RE5        # Ch A = 5½ digits
DSP1,AZ1        # Ch A = auto-zero ON

DSP2,F35        # Ch B = DCI (10 A)
DSP2,PR2        # Ch B = MED
DSP2,RE4        # Ch B = 4½ digits
DSP2,AZ0        # Ch B = auto-zero OFF

Reading Dual Data

# Via SD0 (both channels in one read):
raw = instrument.read()        # "BDV_ +3.29860E+00, DCV_ +1.02400E-01"
val_a, val_b = parse_dual_response(raw)

# Or single-channel reads:
instrument.write("DSP1")       # Select Ch A
raw_a = instrument.read()

instrument.write("DSP2")       # Select Ch B
raw_b = instrument.read()

SCPI Command Reference Overview

The 7352A also supports SCPI commands (select LANG SCPI in the I/F menu). The GUI uses ADC mode only, but the console tab works with SCPI commands too. Common mappings:

Warining: I haven't tested the SCPI interface.

ADC Command	SCPI Equivalent
F1	:SENS:FUNC "VOLT:DC",(@1)
F2	:SENS:FUNC "VOLT:AC",(@1)
F12	:SENS:FUNC "VOLT:BDC",(@1)
R4	:SENS:VOLT:DC:RANGE 1.99999,(@1)
PR2	:SENS:VOLT:DC:SRATE MED
RE5	:SENS:VOLT:DC:DIGIT 5,(@1)
AZ1	:SENS:ZERO:AUTO ON
DE1	:DISP:WIND2:STAT ON
SD0	:FORM:READ:MCH BOTH
SD1	:FORM:READ:MCH 1
TRS0	:TRIG:SOUR IMM
TRS3	:TRIG:SOUR BUS
*IDN?	*IDN?
*RST	*RST
*TRG	*TRG
ERR?	:SYST:ERR?

SCPI commands use (@1) for first display and (@2) for second display, e.g.:

:SENS:FUNC "CURR:BDC",(@2)    # Bch DCI
:SENS:CURR:BDC:RANGE 9.99999,(@2)  # 10 A range

GUI Features

CHANNELS Tabbed Panel

• Ch A / Ch B tabs in a single collapsible group
• Enable checkbox per channel (Ch B disabled by default)
• Function combo (populated with channel-appropriate keys)
• Range combo (auto-populated based on selected function)
• Rate, Digits, Auto-Zero controls
• [Apply] button sends settings to the instrument

Plot Tab

• Dual Y-axis OpenGL plot using EnhancedGLPlot / _GLPlotWidget
• Left Y-axis (green): Channel A
• Right Y-axis (cyan): Channel B
• Shared time axis with configurable buffer (default 600 points)
• Crosshair showing both channel values at cursor position
• Markers: M1 (left click on Ch A), M2 (right click on Ch B), with delta readout
• Middle-mouse drag to pan; scroll to zoom
• Toolbar: Auto Zoom, Clear, Fill toggle, Ch B toggle
• Data point count overlay at top

Statistics Tab

• Per-channel staticstics computed locally:
  • Count, Min, Max, Avg, StdDev, Pk-Pk
• Color-coded labels (green = Ch A, cyan = Ch B)
• [Reset] button clears accumulated data

Export Tab

• CSV or TXT format selection
• Timestamp column toggle
• [Start Export] creates a date-stamped file in the working directory
• [Stop Export] closes the file
• Appends each acquired reading row by row

Console Tab

• Command entry field with autocomplete for all ADC commands
• Command history via Up/Down arrow keys
• [Send] button + Enter key to transmit
• [Clear] button to clear the console log
• Response and status display in the log area
• Supports any ADC or SCPI command — useful for testing and debugging

Themes

• View → Dark Theme toggle (default: dark)
• Persisted across sessions via QSettings
• Light theme: light background, dark text, adjusted plot colors
• Both themes use CSS-style QSS + dynamic ThemeColors for live elements

Configuration Persistence

The following settings are saved/restored via QSettings:

• Window geometry and state (position, size, maximized)
• Channel A/B enabled state
• Last function for Ch A and Ch B
• Read interval
• Dark theme preference

Real-Device Validation

Instrument Behavior Discoveries

The following behaviors were confirmed via hardware testing with an ADCMT 7352A (firmware A01):

Function query format: F? returns zero-padded two-digit function codes for single-digit functions (F01, F02, F03, F05). F50 returns as-is. The GUI parser handles both formats; the comparison is normalized in the test suite using _fk_eq().

Per-display RE setting: RE (digits) is stored per-display (DSP1/DSP2), while PR (rate) is shared globally. Setting DSP2,RE4 does not change the value returned by a bare RE? query (which reflects display 1). To query display 2's digits, use DSP2,RE?. The GUI's per-channel apply methods (apply_settings_ch_a/b) correctly use the DSP prefix for writes.

Statistics require MN1: The MAX/MIN calculation (MN1) must be enabled before AVN?, MAX?, MIN?, and AVE? accumulate readings. After *RST, MN0 is the default; stats queries return zero/placeholder values until MN1 is set.

SD2 for Ch B only: Reading channel B in single-display mode requires SD2 output mode, not SD1 + read_channel("B"). The worker was fixed to use enable_dual_display(False) + set_output_mode("SECOND") when only Ch B is enabled, replacing the previous read_channel approach which returned display 1 data regardless of the DSP2 prefix.

Read interval: With INIC1 continuous mode and SD1, the instrument produces data faster than the acquisition loop's 200ms interval when in FAST rate. The timing test confirmed intervals averaging ~223ms (target 200ms, ±50% tolerance), dominated by Python's time.sleep accuracy and USB bulk transfer latency.

Worker Acquisition Modes

Mode	Channels	DE	SD	Read method
BOTH	A + B	DE1	SD0	read_dual()
FIRST	A only	DE0	SD1	read()
SECOND	B only	DE0	SD2	read()

Test Results Summary

All 22 tests pass on hardware. The suite covers: connection, init, all per-channel settings (function, range, rate, digits, auto-zero via DSP1/DSP2 prefixes), calculations (NL, SM+TI, SC, DB, MN, CO+HI/LO), all 10 read stats queries (including SCNT/SMAX/SMIN/SAVE/SSIG/SPTP), single/dual/worker acquisition sequences, continuous free-run, interval timing, error queue, status registers, and cleanup.

Disclaimer

I used LLMs extensively during the development process. Tests have been conducted using a real device, but I hold no responsibility for the program outcomes. The code is free to reuse.