Agilent U12xxx series
The Agilent U12xxx series are handheld digital multimeters, ranging from inexpensive all-purpose meters to industrial meters.
| Model | Counts | Supported |
|---|---|---|
| U1231A | 6000 | Yes |
| U1232A | 6000 | Yes |
| U1233A | 6000 | Yes |
| U1241A / U1241B | 10000 | Yes |
| U1242A / U1242B | 10000 | Yes |
| U1251A / U1251B | 50000 | Yes |
| U1252A / U1252B | 50000 | Yes |
| U1253A / U1253B | 50000 | Yes |
| U1271A | 30000 | No |
| U1272A | 30000 | No |
| U1273A | 30000 | No |
| U1273AX | 30000 | No |
Is your model not supported yet? Get in touch! We need people to help us test other models in this series, and getting a new model supported is generally quick & easy.
Connection
All models communicate via an optically isolated serial connection, at 9600 bps, 8 bits, no parity, and 1 stop bit (9600/8n1). Connecting to the devices can be done either via USB (U1173A cable) or Bluetooth (U1177A interface).
Protocol
All models in this series use generally the same protocol, with only minor differences between models -- and none within the same range.
*IDN?
Sending the command *IDN? causes the device to return a comma-separated four-field string, compatible with the identical GPIB command. The four fields are vendor name, model name, serial number and version:
Agilent Technologies,U1232A,MY52020136,V1.00
*RST
Sending the command *RST causes the device to reset. The response is an asterisk followed by the current dial position, for example *1 indicates the first position.
SYST:BATT?
The command SYST:BATT? returns a value indicating the device's battery level. The value is in a different format depending on the model series:
The U123xx models return a percentage value, like this:
36%
The U124xx models return a value like this:
+1.04200000E+02
SYST:BEEP
The command SYST:BEEP TONE make the multimeter emit a beep.
SYST:BLIT
The commands SYST:BLIT 1 and SYST:BLIT 0 turn the screen backlight on and off. There is no response. The backlight timer will still run and turn the backlight back off again if it is enabled.
FETC?
The FETC? command returns the current measured value, as a floating point ASCII string, as in the following examples:
+9.25000000E-03 +0.00000000E+00 -1.01140000E+00 -9.10200000E-01
The sign characters are always present, and the value is always in normalized scientific format. This applies even when in a mode that uses integer numbers, 11 would be transmitted as +1.10000000E+01. If no valid measurement is available, i.e. the display shows "OL" or "-OL", the transmitted value is either +9.90000000E+37 and -9.90000000E+37 respectively.
CONF:
The CONF: commands can be used to change modes and ranges on the multimeter. It is not to be confused with the CONF? query described below.
For a given rotary switch position, only those CONF: commands work that switch to modes that can be reached by pressing the range or shift buttons.
U123xx models
| Command | Rotary Switch Setting | Meaning |
|---|---|---|
CONF:VOLT:AC
|
Any voltage mode | Switch to Volts AC mode with autoranging |
CONF:VOLT:DC
|
Any voltage mode | Switch to Volts DC mode with autoranging |
CONF:VOLT:AC 600
|
Any voltage mode | Switch to Volts AC mode in 600V range. Valid ranges are: 600, 60, 6, 0.6 |
CONF:VOLT:AC 600
|
Any voltage mode | Switch to Volts AC mode in 600V range. Valid ranges are: 600, 60, 6, 0.6 |
CONF:CURR:AC
|
Any current mode | Switch to AC current measurement mode with autoranging |
CONF:CURR:DC
|
Any current mode | Switch to DC current measurement mode with autoranging
|
CONF?
The CONF? command queries the device's current measurement configuration.
U123xx models
This can be either one, two or three comma-separated fields. The number of fields depends on the first field's value, but the second field always denotes the measurement mode's range and resolution, and the third field is the current type (AC or DC). For example, this indicates AC voltage in the 600mV range:
V,0,AC
| Mode | Resolution | Current | Meaning |
|---|---|---|---|
| V | y | y | Volts |
| 0 | Range 600mV, resolution 0.1mV | ||
| 1 | Range 6V, resolution 1mV | ||
| 2 | Range 60V, resolution 0.01V | ||
| 3 | Range 600V, resolution 0.1V | ||
| MV | y | y | Millivolts |
| 1 | Range 600mV, resolution 0.1mV | ||
| A | y | y | Ampere |
| 0 | Range 6A, resolution 1mA | ||
| 1 | Range 10A, resolution 0.01A | ||
| UA | y | y | Microampere |
| 0 | Range 60μA, resolution 0.01μA | ||
| 1 | Range 600μA, resolution 0.1μA | ||
| FREQ | y | y | AC frequency |
| 0 | Always shows 0, even when the range is changed manually on the device. This is possibly a firmware bug. | ||
| RES | y | n | Resistance |
| 0 | Range 600Ω, resolution 0.1Ω | ||
| 1 | Range 6kΩ, resolution 0.001kΩ | ||
| 2 | Range 60kΩ, resolution 0.01kΩ | ||
| 3 | Range 600kΩ, resolution 0.1kΩ | ||
| 4 | Range 6MΩ, resolution 0.001MΩ | ||
| 5 | Range 60MΩ, resolution 0.01MΩ | ||
| CAP | y | n | Capacitance |
| 0 | Range 1000nF, resolution 1nF | ||
| 1 | Range 10μF, resolution 0.01μF | ||
| 2 | Range 100μF, resolution 0.1μF | ||
| 3 | Range 1000μF, resolution 1μF | ||
| 4 | Range 10mF, resolution 0.01mF | ||
| DIOD | n | n | Diode |
U124xx and U125xx models
The output consists of the meter's mode, followed by a space, and then the meter's upper and lower ranges in that mode, separated by a comma. The mode may optionally include a colon followed by a code denoting a submode relevant to that major mode. For example, this is the AC voltage in the 1000mV range:
VOLT:AC +1.000000E+00,+1.000000E-04
| Mode | Meaning |
|---|---|
| VOLT | Voltage, submode can be AC |
| CURR | Current, submode can be AC |
| FREQ | Frequency counter |
| DIOD | Diode check |
| CONT | Continuity |
| RES | Resistance |
| CAP | Capacitance |
| SCOU | Switch counter |
| CPER | Current loop, submode can be e.g. 0-20mA or 4-20mA.
|
| T1 or T2 | Temperature, submode can be K or J, denoting the thermocouple type. Instead of range, CEL or FAR is given, denoting the measurement is in Celcius or Fahrenheit. |
STAT
The STAT? command is used to query the current state of the device. The response is a quoted 21-byte string, like this:
"000000000110L00000000"
U123xx models
| Byte | Value | Meaning |
|---|---|---|
| 1 | Max/min/avg mode | |
| 0 | Off | |
| 1 | On | |
| 2 | Relative measurement. The last value returned from FETC? before this mode was enabled denotes the stored reference value. | |
| 0 | Off | |
| 1 | On | |
| 3 | Trig hold-log | |
| 0 | Off | |
| 1 | On | |
| 4 | Auto hold-log | |
| 0 | Off | |
| 1 | On | |
| 5 | LED flashlight | |
| 0 | Off | |
| 1 | On | |
| 6 | LCD backlight | |
| 0 | Off | |
| 1 | On | |
| 7 | Smoothing | |
| 0 | Off | |
| 1 | On | |
| 8 | Temp/aux mode. When on and rotary switch is in position 5 (capacitance), CONF? returns MV,1,DC, but the value returned from FETC? instead denotes the temperature, in the unit (F or C) according to the meter's configuration.
| |
| 0 | Off | |
| 1 | On | |
| 9 | Unknown (always 0) | |
| 10 | Beep frequency | |
| 0 | 4.2kHz | |
| 1 | 3.8kHz (default) | |
| 2 | 3.4kHz | |
| 3 | 3.2kHz | |
| 4 | Off | |
| 11 | Auto power-off (APO) | |
| 0 | Off | |
| 1 | On | |
| 12 | Unknown (always 0) | |
| 13 | Unknown (always L) | |
| 14-15 | Unknown (always 0) | |
| 16 | Rotary switch position | |
| 0 | V/Zlow | |
| 1 | Voltage AC | |
| 2 | Voltage DC | |
| 3 | Resistance | |
| 4 | Diode | |
| 5 | Capacitance | |
| 6 | Current | |
| 7 | Microcurrent | |
| 17 | Continuity mode. When enabled, the value returned from FETC? is either NAN (no continuity) or any real value to denote continuity. | |
| 0 | Off | |
| 1 | On | |
| 18 | Unknown (always 0) | |
| 19 | Battery low indicator | |
| 0 | Battery OK | |
| 1 | Battery low | |
| 20-21 | Unknown (always 0) |
U124xx models
| Byte | Value | Meaning |
|---|---|---|
| 1 | Max/min/avg mode | |
| 0 | Off | |
| 1 | On | |
| 2 | Relative measurement. The last value returned from FETC? before this mode was enabled denotes the stored reference value. | |
| 0 | Off | |
| 1 | On | |
| 3 | Unknown | |
| 4 | Unknown | |
| 5 | Unknown | |
| 6 | Current loop mode | |
| 0 | 0-20mA mode | |
| 1 | 4-20mA mode | |
| 7 | Unknown (always I) | |
| 8 | Hold mode. | |
| 0 | Off | |
| 1 | On | |
| 9 | Unknown | |
| 10 | Beep frequency | |
| 0 | Off (no beeps) | |
| C | 300Hz | |
| F | 600Hz | |
| 1 | 1.2kHz | |
| 2 | 2.4kHz | |
| 11 | Auto power-off (APO) | |
| 0 | Off | |
| 1 | On | |
| 12 | LCD backlight | |
| 0 | Off | |
| 1 | On | |
| 13 | Unknown (always L) | |
| 14 | Unknown | |
| 15 | Unknown | |
| 16 | Rotary switch position | |
| 0 | Voltage | |
| 1 | Diode | |
| 2 | Resistance | |
| 3 | Capacitance | |
| 4 | uA | |
| 5 | mA | |
| 6 | A | |
| 7 | Temperature | |
| 17 | Unknown | |
| 18 | Unknown (always 1) | |
| 19 | Unknown | |
| 20 | Switch counter mode | |
| 0 | increase count on rising flank (initially low) | |
| 1 | increase count on falling flank (initially high) | |
| 21 | Auto range | |
| 0 | Off | |
| 1 | On |
U125xx models
| Byte | Value | Meaning |
|---|---|---|
| 1 | Max/min/avg mode | |
| 0 | Off | |
| 1 | On | |
| 2 | Relative measurement. The last value returned from FETC? before this mode was enabled denotes the stored reference value. | |
| 0 | Off | |
| 1 | On | |
| 3 | dB mode | |
| 0 | Off | |
| m | ? | |
| V | ? | |
| 4 | Unknown | |
| 5 | Peak hold mode | |
| 0 | Off | |
| 1 | On | |
| 6 | Current percent | |
| 0 | 0-20mA | |
| 1 | 4-20mA | |
| 7 | Triggerhold I/B ? | |
| 8 | Triggered hold mode. | |
| 0 | Off | |
| 1 | On | |
| 9 | Zero temperature compensation? | |
| 10 | Beep selection ? | |
| 11 | Auto power-off (APO) | |
| 0 | Off | |
| 1 | On | |
| 12 | LCD backlight | |
| 0 | Off | |
| 1 | On | |
| 13 | Unknown (always L) | |
| 14 | Unknown (always 0) | |
| 15 | Unknown | |
| 16 | Rotary position ? | |
| 17 | Output status active/standby ? | |
| 18 | Unknown | |
| 19 | Battery low indicator | |
| 0 | Battery OK | |
| 1 | Battery low | |
| 20 | Frequency counter prescaler | |
| 0 | No prescaling | |
| 1 | Divide by 100 | |
| 21 | Auto range | |
| 0 | Manual range | |
| 1 | Auto range |