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PSU — Power Supply

Auto-generated reference

For the definitive command list extracted directly from source code, see REPL Command Reference.

Controls power supply units over VISA.

  • Single-channel PSUs (e.g. HP E3631A): channel is always 1
  • Multi-channel PSUs (e.g. Matrix MPS-6010H): channels 1, 2, 3, or all
  • Multiple PSUs are named psu1, psu2, etc.

Address a specific PSU directly: psu1 set 5.0 -- or use use psu1 then psu set 5.0.

PSU: Set Voltage and Measure

Triple-output power supply. Channels: 1 (0–6 V), 2 (0–25 V), 3 (0– −25 V). Supports tracking mode for ±supply configurations.

Triple-output power supply. Channels: 1 (0–6 V / 5 A), 2 (0–30 V / 1 A), 3 (0–30 V / 1 A). USB/LAN interface. Supports tracking mode, OVP/OCP protection, save/recall (5 slots).

Single-channel programmable PSU with serial interface. Supports remote mode control.

psu chan

Enable or disable an output channel.

psu chan <on|off>

psu chan <channel> <on|off>
Parameter Required Values Description
channel multi-ch only 1, 2, 3, all Channel number. Omit entirely for single-channel PSUs. Use all to toggle all channels at once.
on\|off required on, off on = enable output voltage; off = disable output. 
psu chan on          # enable output (single-channel PSU)
psu chan off         # disable output (single-channel PSU)
psu chan 2 off       # disable channel 2 (multi-channel PSU)
psu chan all off     # disable all channels at once

psu set

Set output voltage and optional current limit. Channel is always required.

psu set <channel> <voltage> [current]
Parameter Required Values Description
channel required 1, 2, 3 Channel number. Single-channel PSUs use 1.
voltage required float (V) Target output voltage in volts.
current optional float (A) Current limit in amperes. If omitted, the current limit is unchanged. 
psu set 1 5.0             # channel 1 to 5 V
psu set 1 5.0 0.5         # channel 1: 5 V, 0.5 A limit
psu set 2 12.0            # channel 2 to 12 V
psu set 2 12.0 1.0        # channel 2: 12 V, 1 A limit

psu meas

Measure and print the live output value. Channel is always required.

psu meas <channel> <v|i>
Parameter Required Values Description
channel required 1, 2, 3 Channel to measure. Single-channel PSUs use 1.
v\|i required v, i v = measure output voltage; i = measure output current. 
psu meas 1 v       # channel 1 voltage
psu meas 1 i       # channel 1 current
psu meas 2 v       # channel 2 voltage

Note

psu meas prints the value but does not record it. To record for export or calculations, use the assignment syntax: label = psu meas 1 v unit=V.

Recording measurements

Use assignment syntax to measure and store the result to the measurement log in one step:

<label> = psu meas <channel> <v|i> [unit=<str>]
Parameter Required Values Description
label required string, no spaces Name for this entry in the log. Appears as the row identifier in log print output. Also used as the bare variable name in calc expressions. Use underscores instead of spaces — e.g. ch1_voltage.
channel required 1, 2, 3 Channel to measure. Single-channel PSUs use 1.
v\|i required v, i Quantity to measure: v = voltage, i = current.
unit= optional string Unit label shown in log print output (e.g. V, A). Display-only — does not affect the stored numeric value or any calculation. 
ch1_v = psu meas 1 v unit=V       # store channel 1 voltage
ch1_i = psu meas 1 i unit=A       # store channel 1 current
ch2_v = psu meas 2 v unit=V       # store channel 2 voltage

After storing, view with log print or compute derived values with calc:

psu_v = psu meas 1 v unit=V
psu_i = psu meas 1 i unit=A
calc power psu_v * psu_i unit=W    # compute power
log print

See Log & Calc for full details.

psu get

Show the programmed voltage/current setpoints (not the live measured output).

psu get

For live measured values use psu meas.

psu track

Enable or disable channel tracking mode (multi-channel PSUs only).

psu track <on|off>
Parameter Required Description
on\|off required on = link channels in tracking mode (±supply); off = independent control.

In tracking mode the two adjustable channels mirror each other — one outputs positive, the other negative — for split-supply configurations.

psu track on     # enable tracking (±supply mode)
psu track off    # return to independent channel control

psu save / recall

Save or restore voltage/current settings to a numbered slot (multi-channel PSUs only).

psu save <1-3>
psu recall <1-3>
Parameter Required Values Description
1-3 required 1, 2, 3 Slot number to save to or recall from. 
psu save 1      # save current settings to slot 1
psu recall 1    # restore settings from slot 1

psu on / psu off

Enable or disable the power supply output (shorthand).

psu on     # enable output
psu off    # disable output

Equivalent to psu chan on / psu chan off. Works on both single-channel and multi-channel PSUs.

psu state

psu state <on|off|safe|reset>
Value Effect
on Enable output
off Disable output
safe Outputs off, voltage setpoints zeroed
reset *RST — factory defaults

Tips & Gotchas

Per-model quirks that trip students up most often.

HP E3631A

  • Triple output with shared ground. Channels 1 (0 to 6 V), 2 (0 to 25 V), and 3 (0 to -25 V) share a common ground. You cannot float them independently.
  • Tracking mode links channels 2 and 3 for +/- supply configurations. Use psu track on.
  • No current readback below ~1 mA. Very low currents read as 0. Use an external DMM for milliamp-level measurements.
  • Output enable is per-channel. You must run psu chan 1 on before psu set 1 5.0 produces any output.

Keysight EDU36311A

  • OVP/OCP protection. Over-voltage and over-current protection can trip and latch off the output. Check the front panel if the output unexpectedly drops to 0.
  • 5 save/recall slots. Use psu save 1 and psu recall 1 to store and restore setups.
  • USB enumeration delay. After connecting, wait 5-10 seconds before running scan. The USB interface takes time to initialize.

Matrix MPS-6010H

  • Serial interface with slow command response. Allow 100-200 ms between commands. The toolkit handles this automatically, but manual raw commands may need sleep 0.2 between them.
  • Remote mode must be enabled. The toolkit does this automatically on first command.

General PSU tips

  • Always sleep after setting a voltage. PSU outputs need 100-500 ms to settle. Without this delay, your DMM will read an intermediate value.
  • Use all off before disconnecting. This safely disables all outputs before you unplug anything.