HH PLI Serie Slider EN

PLI Series - Powerful

Features of performance
Model overview
  • Input voltage up to 1,200 V
  • Load current up to 2,700 A
  • Power from 600 W to 28,800 W
  • Temporary power overload capacity, depending on model
  • Models with integrated zero-volt supply (ZV models)
  • Models with several current setting and measuring ranges (MR models)
  • High power density up to 2,100 W in 2 U (3,200 W in 3 U)
  • Basic operating modes CC - CV - CR - CP
  • Combined operating modes CC+CV, CR+CC+CV, CP+CC+CV, CV+CC
  • Ethernet + USB + RS-232 + CAN as standard
  • GPIB optional
  • Intuitive operation
  • Quick operation by shortcuts
  • Setting toggling
  • Constant current, voltage, resistance and power mode
  • MPP Tracking
  • Digital Master-Slave operation
  • Energy storage test
  • Ri measurement
  • Dynamic load with synchronous DAQ
  • Trigger model
  • SCPI programming with measurement
  • USB MSD as measurement data memory
  • Adjustable protections for overcurrent and undervoltage
  • Analog monitoring outputs for voltage and current
  • Analog control input
  • Digital input and programmable control output
  • Silent fan cooling
  • Settings saving
  • Electronic protection
  • Bilingual help system (German and English)
  • 2 free calibrations (with device registration)

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All-rounders from H&H: the PLI series. With a huge model range, many standard functions, locally operated via the intuitive user interface or remotely via one of the many standard interfaces. Programming is done in SCPI syntax with a high command volume.

Zero-Volt Models - PLIxxxxZV

Special applications, such as fuel cell tests, need to load the DUT down to almost 0 V. For these purposes we supply a range of models with an integrated zero-volt supply. When I/O port signals are to be used, the GND of the I/O port must be galvanically isolated from the negative load input. Therefore we recommend to install the optional galvanically isolated I/O port (option PLI06) at these models.

Multi-Range Models - PLIxxxxMR

A model variant with 3 or 4 "real" current ranges allows the setting and measurement of current, power and resistance over a wide range of values with high resolution and accuracy. Especially solar and PV applications have high requirements at this point. The ranges are graduated with factor 10 each.

Operating Modes and Functions

Basic and Combined Operating Modes
The devices have the operating modes constant current (CC), constant voltage (CV), constant resistance (CR) and constant power (CP). Furthermore, protection values for undervoltage and overcurrent can be set in each operating mode. This results in the combined operating modes CC+CV, CR+CC+CV, CP+CC+CV, CV+CC.
Dynamic Load with List  Function
Dynamic operation (LIST function) can be configured by up to 300 list point settings. The electronic load saves the synchronously acquired measurement data with timestamp.
Data Acquisition
An automatic data acquisition function allows to store measurement data internal or directly on an external USB flash drive.
Energy Storage Test/Discharge Function
The discharge function discharges energy storage devices such as accumulators, batteries, ultracaps etc. in a controlled manner under definable switch-off conditions. The values determined in the process, such as charge and energy, can be read locally and via a data interface.
Internal Resistance Measurement
The electronic load can measure the DC internal resistance of the connected test object. For this purpose it uses a calculation method which is specified in various standards, e.g. DIN EN 61951, DIN EN 61960.
Master-Slave Operation
To increase the power or current, up to 5 equal devices can be operated in parallel in a master-slave connection. The system behaves in the network externally like one single device. The master unit controls the total current of the system, displays the total measured values and supplies these when queried via one of the data interfaces. Cabling: One set each of K-MS-PLI and K-MS-CAN master-slave cables on all slave units (to be purchased from H&H or assembled by the user). To be able to tap monitor signals etc. when using the master-slave cable K-MS-PLI, we offer a SubD25 coupler as an accessory. (Limited scope of functions in master-slave mode. Control via CAN interface not possible).
Watchdog Function
If the watchdog function is activated, the load input is switched off in case of faulty communication with the control PC in order to protect the connected DUT.
MPP Tracking (option PLI21)
The Maximum Power Point Tracking (MPPT) function is used to test solar or photovoltaic modules. For this purpose the maximum power point (MPP) of the connected DUT is controlled in CV mode.
Trigger Model
A configurable trigger model controls data acquisition, static and dynamic settings.

Loading Capacity

The model range covers power classes from  600 W, up to 28,000 W continuous power rating. In addition the models up to 300 V have an overload capability. The height and duration of the possible overload depends on the temperature of the power stage. The unit indicates the currently possible overload. Therefore the units can be used  even for considerably more powerful applications.


  • Current limitation
  • Power limitation
  • Overtemperature protection
  • Protection of the  GND lines at the  Analog I/O Port

Data Interfaces

The following data interfaces are included as standard:
  • Ethernet
  • USB
  • RS-232
  • CAN
Optionally deliverable:
  • GPIB (option PLI02)
LabVIEW drivers are certified by National Instruments.

Analog I/O Port

The standard analog I/O port provides the following functions:
  • Load setting C and V
  • Analog setting of C and V protections
  • Load on-off
  • Operationg mode selection
  • Voltage monitor output
  • Current monitor output
  • Trigger input
  • Trigger output
  • Digital input
  • Programmable control output

Galvanically Isolated Analog I/O Port

For the galvanic isolation between the Analog I/O Port and the load terminals the PLI06 option can be installed. Isolation voltage is 800 V. Using this board also prevents ground loops.

Help System

A help system for most menu items is integrated in the user interface. The help system's language can be set to German or English.


A free Factory Calibration Certificate (FCC) is supplied with the devices. The calibration process is subject to supervision in accordance with DIN EN ISO 9001. The calibration certificate documents the traceability to national standards to illustrate the physical device in accordance with the international System of Units (SI). Within the 2-year warranty period, we will calibrate a second time free of charge if the respective device (serial number) will have been registrated at H&H.
--> Conditions for a second free calibration
For use under laboratory conditions, H&H recommends a calibration interval of 2 years. This is an empirical value that can be used as a guide for the first period of use. Depending on the intended use, service life, relevance of the application and ambient conditions, the operator should adjust this interval accordingly.


We supply a user manual as pdf file and printed General Safety Instructions, each in German and English.

Series PLI

PLI Standard

PLI models with standard setting ranges

PLI EC - Extended Current Range

PLI models with extended current range.

PLI MR - Multiple Current Ranges

PLI models for setting and measuring smallest currents with high accuracy and resolution.

PLI HV - 1200 V

PLI models for high input voltages.

PLI ZV - from 0 V

PLI models with an integrated Zero-Volt-Supply for applications needing to load the DUT down to almost 0 V.


Software Tool for control of PLI (up from FW 4.3.0), PLI-MR (up from FW 1.0.0), ERI (up from FW 2.0.0), TRL (up from FW 1.0.0) and SCL (up from FW 1.0.0) loads.
Software tool for transmission of single commands via GPIB/RS-232/Ethernet/CAN
Software tool to control PLI loads with firmware revision up from AI3.7 DI3.3 UI3.4 (PLI-MR devices are currently not supported)
Software tool (old revision) to control PLI loads with firmware revision from AI2.7 DI2.7 UI2.7 to AI2.9 DI2.9 UI2.9
Software tool (old revision) to control PLI loads with firmware revision from AI2.6 DI2.5 UI2.5 to AI2.6 DI2.6 UI2.6
Release notes PLI software tool
FTDI Driver
Virtual COM port (VCP) Driver from FTDI.


Application 01
Source-Sink with power supply and H&H PLI electronic load
Application 20
Range switching with multi-range loads
Application 03
Simulation of exponential inrush current
Application 02
Loading of low input voltages with an external auxiliary power supply
Application 19
LAN communication with H&H devices
Application 05
Measuring the characteristics of solar panels
Application 06
Loading an AC voltage with a DC load
Application 07
Applying input voltage and PWM operation
Application 09
Simple battery simulation with a PLI electronic load and a power supply
Application 11
Energy storage test and internal resistance measurement with PLI series electronic loads
Application 12
PLI series - programmable load profile, trigger system and its capabilities
Application 13
Realization of a CSV load profile
Application 15
Testing chargers with Charger Starter Interface for PLI series loads
Customer Application 21
Testing and Optimizing Fuel Cell Stacks
Application 17
Connecting several PLI series loads in parallel with master-slave connection
Customer Application 22
Testing Inductive Charging Systems
Customer Application 23
Testing of a Low-Voltage Accumulator for an Electric Racecar