Stanford Research High Voltage Power Supply PS350 - Control via GPIB


The GPIB Interface

Example Session

Sent commands are marked using the symbol >. This character was not actually sent, it only serves to see if a line has been sent or received. I added comments in lines starting with #:

> *IDN?
> *RST
# ↑ got no response (even when waited for 5 seconds)
> VSET100.0;VSET?
> *STB? 7
# ↑ indicating high voltage is on
> *STB?
# ↑ This is the decimal representation of the 8 bits in the serial poll status register:
#   1 0 0 0 0 0 0 1
> *PSC?
> *STB?
> *STB?

A wait time between sending the command VSET100.0;VSET? and getting the response back of 0.014 was the minimum that worked (when using the Prologix USB-to-GPIB adapter via LabView on a Win7 machine). No error output was found at > 0.028 seconds. So a wait time of 0.05 seconds should be safe.


  • HVOF switch HV power output off
  • HVON switch HV power output on
  • IOUT? query the actual current on the HV output
  • VOUT? query the actual voltage on the HV output
Setting Control Commands
  • *RCL i recall the settings (i may be 0 to 9, 0: default settings)
  • *SAV i recall the settings (i may be 1 to 9)
  • ILIM(?) x set / query the current limit value in Amperes (1 mA = 1E-3)
  • ITRP(?) x set / query the current trip value in Amperes (1 mA = 1E-3)
  • SMOD? query if voltage can be controlled by front panel / GPIB or via rear panel analog voltage control input
  • TCLR clear voltage or current trips
  • TMOD(?) i trip reset mode (i = 0: manual trip reset, i = 1 auto trip reset)
  • VLIM(?) x voltage limit setting (sign must match output polarity, VLIM must >= VSET)
  • VSET(?) x voltage setting (sign must match output polarity)
Interface Control Command
  • *RST reset PS350 to default configuration ( = holding down "CLR " at power on)
  • *IDN? queries device configuration; format of return string; StanfordResearchSystems,PS3XX,serial number,version number
Status Reporting Commands

The PS300 reports on its status by means of two status bytes: the serial poll byte, and the standard status byte.

Serial Poll Status Byte

bit name usage
0 stable VSET or ILIM value is stable (depends on whether the PS3X0 is in constant current or constant voltage mode)
1 v trip Voltage trip has occurred.
2 itrip Current trip has occurred.
3 ilim Current limit condition has occurred.
4 MAV GPIB output queue is non-empty.
5 ESB an unmasked bit in the standard status byte has been set
7 hvon indicates that high voltage is on

A service request (SRQ) will be sent whenever one of these bits is set AND the corresponding bit in the serial poll enable register is set. Note that any status condition will produce only one SRQ even if it is never cleared. The vtrip, itrip and ilim bits are latched bits. They are set on the occurrence of the appropriate event and stay set until either the status byte is read or the *CLS command is sent. This allows one to detect if a trip condition has ever occurred. All of the other bits indicate the current states of their respective functions.

The Standard Event Status Byte is defined by the IEEE-488.2 and is not very useful here.

  • *CLS clear all status registers
  • *ESE (?) j set the standard status byte register to j
  • *ESR? {j} Read the standard status register (or only byte j), cleared after reading
  • *PSC (?) j power on status clear (j = 1: all status registers and enable registers are cleared on power up, j = 0: status enable registers maintain their values at power down)
  • *SRE (?) j sets the value of the serial poll enable register. When
  • *STB? {j}

GPIB Error Codes

  • Err6 Syntax Error over GPIB.
  • Err7 Illegal Parameter entered over GPIB.
  • Err8 GPIB Output Queue full.

Product Description

Key Features
  • ±5 kV
  • 1 volt resolution
  • 0.001% regulation
  • 0.05% accuracy
  • Programmable limits and trips
  • 0.0015% ripple
  • GPIB interface

The PS300 Series High Voltage Power Supplies — rugged, compact, reliable instruments for just about any high voltage application.

With up to 5 kV output capability, a GPIB computer interface, and 0.001% voltage regulation, these high voltage power supplies have become the industry standard.

The PS310, PS325 and PS350 are dual-polarity, 25 W supplies. All of the instruments are arc and short-circuit protected with separate programmable hard and soft current limits, making it possible to use them as constant current sources.

The Right Features:
You’ll appreciate the convenience and versatility of the PS300 Series. Two large LED displays monitor the output voltage and current being delivered to your load. Overload reset, limit and trip status, local/remote state, and high voltage enable are also displayed, so you can monitor the instrument status at a glance. A highly visible red LED always indicates when the high voltage is on.

Easy to Use:
Operation is simple — The parameter being adjusted or set is displayed separately and can be entered without affecting the actual output voltage. Up to nine instrument configurations can be stored and recalled at any time, making it easy to run multiple tests.

Remote Programming:
GPIB is available as an option on the 25 W instruments. All parameters can be set and read via the computer interfaces.

Analog Monitoring and Control:
A rear-panel analog input allows the high voltage output to be programmed by a 0 to 10 VDC signal. Two rear-panel analog outputs provide output voltage and current monitoring capabilities. These outputs drive up to 10 mA of current and have 1 O output impedance.

Performance and Value:
The PS300 Series High Voltage Power Supplies are as useful in the R&D lab as they are in automated test applications. Wherever you are using them, the PS300 Series provide proven reliability and performance at a very affordable price.

Voltage Output Specifications:
  • Output Voltage: ± 50 VDC to 5 kV
  • Maximum Current: 5 mA
  • Voltage Set Accuracy: 0.01% +0.05% of full scale
  • Voltage Display Accuracy: Vset accuracy ±1 V, typ. (±2 V, max.)
  • Voltage Resolution: 1 V (set and display)
  • Voltage Resettability: 1 V
  • Voltage Limit Range: 0 to 100% of full scale
  • Voltage Regulation: 0.001% for ±10% line change, 0.005% for 100% load change. Specifications apply for >0.5% (full load) to >1% (no load) of full scale voltage.
  • Output Ripple (Vrms): 0.002% of full scale
  • Current Limit Range: 0 to 105% of full scale
  • Trip Current: 10 µA (min.)
  • Trip Response Time: <10 µs
  • Current Set Accuracy: 0.01% +0.05% of full scale
  • Current Resolution: 1 µA
  • Current Display Accuracy: ±1 µA (typ.), ±2 µA (max.)
  • Stability: 0.01% per hr., <0.03% per 8 hrs.
  • Temperature Drift: 50 ppm/°C, 0°C to 50°C (typ.)
  • Protection: Arc and short circuit protected. Programmable voltage limit, current limit and current trip.
  • Recovery Time: 12 ms for 40% step change in load current (typ.)
  • Discharge Time: <6 s (t0 <1% of full-scale voltage with no load, typ.)

Monitor Output Specifications:

  • Output Scale: 0 to +10 V for 0 to full-scale output regardless of polarity
  • Current Rating: 10 mA (max.)
  • Output Impedance: <1 Ω
  • Accuracy: 0.2% of full scale
  • Update Rate: 8 Hz

External Voltage Set Specifications:

  • Input Scale: 0 to +10 Volts for 0 to full-scale output regardless of polarity
  • Input Impedance: 1 MΩ
  • Accuracy: 0.2% of full-scale
  • Update Rate: 16 Hz
  • Output Slew Rate: <0.3 s for 0 to full-scale under full load.

Mechanical Specifications:

  • HV Connector: Kings Type 1704-1
  • Mating Connection: Kings Type 1705-1
  • Dimensions: 8.1" W x 3.5" H x 16.0" L
  • Weight: 8 lbs.
  • Power: 50 W, 100/120/220/240 VAC, 50/60 Hz