HP 3478A Multimeter
- class pymeasure.instruments.hp.HP3478A(adapter, name='Hewlett-Packard HP3478A', **kwargs)
Bases:
HPLegacyInstrument
Represents the Hewlett Packard 3478A 5 1/2 digit multimeter and provides a high-level interface for interacting with the instrument.
- class ERRORS(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)
Bases:
IntFlag
Enum element for errror bit decoding
- property SRQ_mask
Return current SRQ mask, this property can be set,
bit assigment for SRQ:
Bit (dec)
Description
1
SRQ when Data ready
4
SRQ when Syntax error
8
SRQ when internal error
16
front panel SQR button
32
SRQ by invalid calibration
- property active_connectors
Return selected connectors (“front”/”back”), based on front-panel selector switch
- property auto_range_enabled
Property describing the auto-ranging status
Value
Status
True
auto-range function activated
False
manual range selection / auto-range disabled
The range can be set with the
range
property
- property auto_zero_enabled
Return auto-zero status, this property can be set
Value
Status
True
auto-zero active
False
auto-zero disabled
- property calibration_data
Read or write the calibration data as an array of 256 values between 0 and 15.
The calibration data of an HP 3478A is stored in a 256x4 SRAM that is permanently powered by a 3v Lithium battery. When the battery runs out, the calibration data is lost, and recalibration is required.
When read, this property fetches and returns the calibration data so that it can be backed up.
When assigned a value, it similarly expects an array of 256 values between 0 and 15, and writes the values back to the instrument.
When writing, exceptions are raised for the following conditions:
The CAL ENABLE switch at the front of the instrument is not set to ON.
The array with values does not contain exactly 256 elements.
The array with values does not pass a verification check.
IMPORTANT: changing the calibration data results in permanent loss of the previous data. Use with care!
- property calibration_enabled
Return calibration enable switch setting, based on front-panel selector switch
Value
Status
True
calbration possible
False
calibration locked
- check_errors()
Method to read the error status register
- Return error_status
one byte with the error status register content
- Rtype error_status
int
- display_reset()
Reset the display of the instrument.
- property display_text
Displays up to 12 upper-case ASCII characters on the display.
- property display_text_no_symbol
Displays up to 12 upper-case ASCII characters on the display and disables all symbols on the display.
- property error_status
Checks the error status register
- property measure_ACI
Returns the measured value for AC current as a float in A.
- property measure_ACV
Returns the measured value for AC Voltage as a float in V.
- property measure_DCI
Returns the measured value for DC current as a float in A.
- property measure_DCV
Returns the measured value for DC Voltage as a float in V.
- property measure_R2W
Returns the measured value for 2-wire resistance as a float in Ohm.
- property measure_R4W
Returns the measured value for 4-wire resistance as a float in Ohm.
- property measure_Rext
Returns the measured value for extended resistance mode (>30M, 2-wire) resistance as a float in Ohm.
- property mode
Return current selected measurement mode, this propery can be set. Allowed values are
Mode
Function
ACI
AC current
ACV
AC voltage
DCI
DC current
DCV
DC voltage
R2W
2-wire resistance
R4W
4-wire resistance
Rext
extended resistance method (requires additional 10 M resistor)
- property range
Returns the current measurement range, this property can be set.
Valid values are :
Mode
Range
ACI
0.3, 3, auto
ACV
0.3, 3, 30, 300, auto
DCI
0.3, 3, auto
DCV
0.03, 0.3, 3, 30, 300, auto
R2W
30, 300, 3000, 3E4, 3E5, 3E6, 3E7, auto
R4W
30, 300, 3000, 3E4, 3E5, 3E6, 3E7, auto
Rext
3E7, auto
- property resolution
Returns current selected resolution, this property can be set.
Possible values are 3,4 or 5 (for 3 1/2, 4 1/2 or 5 1/2 digits of resolution)
- status_desc
alias of
Status
- property trigger
Return current selected trigger mode, this property can be set
Possibe values are:
Value
Meaning
auto
automatic trigger (internal)
internal
automatic trigger (internal)
external
external trigger (connector on back or GET)
hold
holds the measurement
fast
fast trigger for AC measurements
- verify_calibration_data(cal_data)
Verify the checksums of all calibration entries.
Expects an array of 256 values with calibration data.
- Return calibration_correct
True when all checksums are correct.
- Rtype calibration_correct
boolean
- verify_calibration_entry(cal_data, entry_nr)
Verify the checksum of one calibration entry.
Expects an array of 256 values with calibration data, and an entry number from 0 to 18.
Returns True when the checksum of the specified calibration entry is correct.
- write_calibration_data(cal_data, verify_calibration_data=True)
Method to write calibration data.
The cal_data parameter format is the same as the
calibration_data
property.Verification of the cal_data array can be bypassed by setting
verify_calibration_data
toFalse
.