Static load modes
CC, CV, CP, CR and LED reproduce different load characteristics and LED driver operating conditions.
NXI-3201 – Modular programmable DC electronic load up to 100 V
For compact multi-channel testing of power supplies, converters and electronic assemblies.
The plug-in design combines fine-resolution dual-range measurement with a compact single- or double-slot format. Voltage, current, resistance and power ranges can therefore be matched to the measurement task without allocating a separate bench instrument to every channel.
Dynamic profiles
CCD, CVD, CPD and CRD generate changing loads with adjustable rise and fall slew rates.
Automated testing
Sequence, auto, Von/Voff, OCP, OPP and short-circuit tests support repeatable test procedures.
LAN and trigger
LAN, SCPI, Modbus-RTU and an external trigger integrate the modules into automated test systems.
Personal project consultation
Do you need support selecting the right power supply? Our technical specialists will provide personal advice tailored to your application.
Select the appropriate technical configuration or access product documentation directly.
ART. NO.
Description
Current [A]
Power [P]
Voltage [V]
NXI-3201-20-1
|
Description
NXI-3201-20-1 DC load module, 20 W, 20 V, 1 A, CC/CV/CR/CP, LAN.
|
Current [A]
1
|
Power [P]
20
|
Voltage [V]
20
|
NXI Module Card
Technical Data
NXI Category
Performance modules
Product category
NXI Measurement & Test Systems
Type of DC Load
Modular Card
Benchtop Unit
NXI-3201-60-1
|
Description
NXI-3201-60-1 DC load module, 50 W, 60 V, 1 A, CC/CV/CR/CP, LAN.
|
Current [A]
1
|
Power [P]
50
|
Voltage [V]
60
|
NXI Module Card
Technical Data
NXI Category
Performance modules
Product category
NXI Measurement & Test Systems
Type of DC Load
Modular Card
Benchtop Unit
NXI-3201-20-5
|
Description
NXI-3201-20-5 DC load module, 50 W, 20 V, 5 A, CC/CV/CR/CP, LAN.
|
Current [A]
5
|
Power [P]
50
|
Voltage [V]
20
|
NXI Module Card
Technical Data
NXI Category
Performance modules
Product category
NXI Measurement & Test Systems
Type of DC Load
Modular Card
Benchtop Unit
NXI-3201-60-5
|
Description
NXI-3201-60-5 DC load module, 50 W, 60 V, 5 A, CC/CV/CR/CP, LAN.
|
Current [A]
5
|
Power [P]
50
|
Voltage [V]
60
|
NXI Module Card
Technical Data
NXI Category
Performance modules
Product category
NXI Measurement & Test Systems
Type of DC Load
Modular Card
Benchtop Unit
NXI-3201-20-10
|
Description
NXI-3201-20-10 DC load module, 50 W, 20 V, 10 A, CC/CV/CR/CP, LAN.
|
Current [A]
10
|
Power [P]
50
|
Voltage [V]
20
|
NXI Module Card
Technical Data
NXI Category
Performance modules
Product category
NXI Measurement & Test Systems
Type of DC Load
Modular Card
Benchtop Unit
NXI-3201-100-1
|
Description
NXI-3201-100-1 DC load module, 25 W, 100 V, 1 A, CC/CV/CR/CP, LAN.
|
Current [A]
1
|
Power [P]
25
|
Voltage [V]
100
|
NXI Module Card
Technical Data
NXI Category
Performance modules
Product category
NXI Measurement & Test Systems
Type of DC Load
Modular Card
Benchtop Unit
NXI-3201 overview
The NXI-3201 is a modular programmable DC electronic load for integrated single- and multi-channel test systems. Six models cover power ratings of 20 W, 25 W or 50 W, input voltages up to 20 V, 60 V or 100 V and currents up to 1 A, 5 A or 10 A. Every module provides one electrically isolated channel that can be controlled independently or together with additional channels. Depending on the model, the modules occupy one or two slots and can be installed in an NXI-F1080 or another chassis from the NXI-F1000 platform. Individual operation is also possible using a 12 V DC supply and LAN communication. Static and dynamic load modes, LED simulation, automated protection-function tests and 500 kHz voltage and current sampling support testing of power supplies, DC/DC converters, LED drivers, batteries and automotive components.
Key benefits
Low operating points
Depending on the model, the specified operating range starts at 0.5 V for testing low-voltage sources with low output impedance.
Fast data acquisition
Voltage and current are sampled at 500 kHz, allowing rapid changes in the device under test to be evaluated promptly.
Short communication response
A specified communication response time of no more than 5 ms supports tightly timed automated test procedures.
Isolated channels
Electrically isolated module channels simplify parallel testing of several independent devices within one chassis.
Accurate programming
Specified programming accuracy reaches 0.025% + 0.025% of full scale in constant-voltage operation.
Four-wire sensing
Remote sense measures voltage directly at the DUT and reduces the influence of voltage drops in the connecting cables.
DC electronic load operating principle
The NXI-3201 draws current from a connected DC device under test and controls the load according to the selected operating mode. Within the permitted voltage, current and power limits, the module can maintain a constant input current, input voltage, power level or defined resistance.
In LED mode, the electrical behaviour of an LED is approximated using a threshold voltage Vf in series with a differential resistance Rd. The resulting characteristic represents the tangent to the nonlinear LED curve at the selected operating point, enabling LED drivers to be tested with an application-specific load characteristic.
When remote sense is enabled, S+ and S− must be connected directly to the DUT output. If the sense lines remain open while four-wire sensing is selected, the input voltage cannot be detected correctly and CV, CR and CP modes will not operate properly.
Models and technical specifications
Model selection is based on the maximum DUT voltage, required load current, absorbed power and available chassis slots. Each module provides one electronic load channel.
| Model | Max. voltage | Max. current | Max. power | Module width | Minimum operating voltage |
|---|---|---|---|---|---|
| NXI-3201-20/10 | 20 V | 10 A | 50 W | Double slot, 8 HP | 0.5 V at 0.5 A; 1.5 V at 10 A |
| NXI-3201-20/5 | 20 V | 5 A | 50 W | Double slot, 8 HP | 0.5 V at 0.25 A; 0.7 V at 5 A |
| NXI-3201-20/1 | 20 V | 1 A | 20 W | Single slot, 4 HP | 0.5 V at 0.05 A; 0.5 V at 1 A |
| NXI-3201-60/1 | 60 V | 1 A | 50 W | Single slot, 4 HP | 0.5 V at 0.05 A; 0.5 V at 1 A |
| NXI-3201-60/5 | 60 V | 5 A | 50 W | Double slot, 8 HP | 0.5 V at 0.25 A; 0.8 V at 5 A |
| NXI-3201-100/1 | 100 V | 1 A | 25 W | Single slot, 4 HP | 0.5 V at 0.05 A; 0.5 V at 1 A |
Measurement and programming ranges
| Model | CV main/fine range | CC main/fine range | CP main/fine range | CR main/fine range |
|---|---|---|---|---|
| NXI-3201-20/10 | 0–20 V / 0–1 V | 0–10 A / 0–0.5 A | 0–50 W / 0–2.5 W | 0.2–500 Ω / 4 Ω–10 kΩ |
| NXI-3201-20/5 | 0–20 V / 0–1 V | 0–5 A / 0–0.25 A | 0–50 W / 0–2.5 W | 0.3 Ω–1 kΩ / 6–20 kΩ |
| NXI-3201-20/1 | 0–20 V / 0–1 V | 0–1 A / 0–0.05 A | 0–20 W / 0–1 W | 0.4 Ω–2 kΩ / 8–40 kΩ |
| NXI-3201-60/1 | 0–60 V / 0–3 V | 0–1 A / 0–0.05 A | 0–50 W / 0–2.5 W | 0.4 Ω–5 kΩ / 8–100 kΩ |
| NXI-3201-60/5 | 0–60 V / 0–3 V | 0–5 A / 0–0.25 A | 0–50 W / 0–2.5 W | 0.3 Ω–1 kΩ / 6–20 kΩ |
| NXI-3201-100/1 | 0–100 V / 0–5 V | 0–1 A / 0–0.05 A | 0–25 W / 0–1.25 W | 0.4 Ω–5 kΩ / 8–100 kΩ |
Programming and readback accuracy
| Operating mode | Programming accuracy | Readback accuracy |
|---|---|---|
| CV | 0.025% + 0.025% of full scale | 0.025% + 0.025% of full scale |
| CC | 0.05% + 0.05% of full scale | 0.05% + 0.05% of full scale |
| CP | 0.1% + 0.1% of full scale | Power calculated from measured voltage and current |
| CR | (Vin/Rset) × 0.1% + 0.1% of current full scale | Dependent on voltage and current measurement |
Accuracy specifications apply at 23 ± 5°C, within one year after calibration and at a relative humidity of up to 80%.
Dynamic response and control behaviour
Load-current rise and fall slew rates are programmable. The available ranges depend on the selected model and whether the main or fine measurement range is active. Control-loop response can also be adjusted to match the DUT and the required stability.
| Models | Main range | Fine range |
|---|---|---|
| NXI-3201-20/10 | 0.01–1,000 A/ms | 0.01–50 A/ms |
| NXI-3201-20/5 and NXI-3201-60/5 | 0.01–500 A/ms | 0.01–25 A/ms |
| NXI-3201-20/1, NXI-3201-60/1 and NXI-3201-100/1 | 0.01–100 A/ms | 0.01–5 A/ms |
In dynamic CCD mode, T1 and T2 can be programmed from 0.016 ms to 60,000 ms or from 0.016 s to 60,000 s. The corresponding time resolution is 1 µs or 1 ms. Adjustable current transitions and dwell times support load-step, periodic-load and repeatable transient tests.
Operating modes and programmable test functions
Constant current
The load maintains the programmed input current for power-supply, battery and overcurrent testing.
Constant voltage
Load current is regulated to maintain a defined voltage at the electronic load input.
Constant power
The module adjusts current as the input voltage changes to maintain constant absorbed power.
Constant resistance
A programmable resistance reproduces resistive loads for power supplies, converters and electrical components.
LED simulation
The combination of Vf and Rd approximates the nonlinear LED characteristic at the selected operating point.
Sequence operation
Editable steps, file links and cycle counts automate multi-stage and repeating load profiles.
| Test function | Purpose | Typical use |
|---|---|---|
| CCD, CVD, CPD and CRD | Dynamic switching between programmed load values | Transient, load-step and stability testing |
| Auto test | Automated execution of defined test steps | Repeatable laboratory, ATE and production testing |
| Von/Voff | Load activation based on defined input-voltage thresholds | Testing DUT turn-on and turn-off behaviour |
| OCP test | Incremental increase of load current until the termination condition is reached | Determining the overcurrent trip point of a power supply |
| OPP test | Testing DUT behaviour while absorbed power is increased | Validation of overpower protection |
| Short-circuit simulation | Controlled reproduction of a very low load impedance | Functional testing of DUT short-circuit response |
Typical applications
The compact module format, static and dynamic load modes and central multi-channel control support development, validation and production testing of low-power DC components.
AC/DC and DC power supplies
Output regulation, load capability and protection functions are tested using static operating points, load steps and OCP or OPP tests.
DC/DC converters
The load reproduces defined current, power or resistance profiles at the converter output.
LED drivers and power supplies
LED mode reproduces an LED operating-point characteristic for functional and control-loop testing of drivers.
Battery discharge testing
Lithium batteries and storage batteries can be discharged under programmed current or power conditions.
Automotive and e-mobility testing
Wiring harnesses, connectors, fuses, relays and electronic assemblies are tested using defined load and protection-test procedures.
Production and end-of-line testing
Multiple isolated channels perform parallel load tests in compact automated manufacturing and ATE systems.
Interfaces, software and automation
| Function | Availability | Description |
|---|---|---|
| LAN | Standard | Direct network connection for individual control, device discovery and automated test systems |
| SCPI | Standard | Remote-control commands for integration into custom test programs and ATE procedures |
| Modbus-RTU | Standard | Supported communication protocol for industrial control and integration tasks |
| TCP/IP | Standard | Network communication with a specified response time of no more than 5 ms |
| External trigger | Standard | Starting or synchronising defined test procedures using an external signal |
| Remote sense | Standard | Four-wire DUT voltage measurement using the S+ and S− terminals |
| NXI chassis interface | Standard | Power, communication and central control within a compatible NXI chassis |
| PC software | Standard | Device discovery, direct operation, SEQ editor, protection settings, configuration and operating log |
The PC software supports Windows 7 or later. Devices on the local network can be discovered automatically or connected manually using the model, IP address and device ID. Static setpoints can be changed during operation. Sequence files can be created, written to the module, linked and executed for a defined number of cycles or continuously.
The operating log stores up to 1,000 operations and identifies detected errors. Protection parameters and application settings can be read, changed and restored to their factory defaults.
Multi-channel scaling within the NXI system
The modules are designed for integration into chassis from the NXI-F1000 platform. A 4U NXI-F1080 chassis supports up to 16 load channels depending on module width and system configuration. Single-slot models occupy 4 HP, while double-slot models occupy 8 HP.
High channel density
Up to 16 channels in one 4U chassis reduce the rack space required for multi-channel test systems.
Combined control
Multiple channels can be operated independently or simultaneously for synchronised load testing.
Individual operation
An external 12 V DC supply and LAN connection allow a module to be controlled outside the chassis.
Installation and infrastructure
| Characteristic | Specification |
|---|---|
| Power supply | 12 V DC ±10%, current consumption below 0.5 A |
| Single-slot dimensions | 130.5 mm high × 20 mm wide × 230.5 mm deep |
| Double-slot dimensions | 130.5 mm high × 40 mm wide × 230.5 mm deep |
| Load and sense connection | Pluggable four-pin connector for LOAD +/− and S+/S− |
| Operating temperature | 0 to 40°C |
| Storage temperature | −20 to 60°C |
| Relative humidity | 5 to 90% RH, non-condensing |
| Altitude | Below 2,000 m |
| Atmospheric pressure | 80 to 110 kPa |
Connections must only be made or removed while the system is switched off. The module or chassis must be properly grounded. Ventilation openings must remain unobstructed, and operation in explosive, wet or condensing environments is not permitted.
Protection and safety functions
Voltage monitoring
OVP and additional OV parameters monitor the input voltage and respond when configured limits are exceeded.
Current protection and OCP test
OCP protects the module, while the separate OCP test determines the overcurrent trip point of the connected DUT.
Power limitation
OPP and OP parameters monitor absorbed power and support testing of external overpower protection functions.
Temperature protection
OTP protects the module against excessive temperature, while additional RV and RC functions extend the monitoring capabilities.
The protection-function set includes OV, OC, OP, OVP, OCP, OPP, OTP, RV and RC. Short-circuit simulation, OCP testing and OPP testing are programmable DUT test functions and do not replace a safety assessment of the complete test setup.
NXI-3201 FAQ
How is the appropriate model selected?
Selection is based on maximum DUT voltage, required load current, absorbed power, minimum operating voltage and the available chassis slot width.
How many channels fit into an NXI-F1080 chassis?
Depending on the combination of single- and double-slot modules, a 4U chassis can accommodate up to 16 channels.
Are the channels electrically isolated?
Yes. Every module channel is electrically isolated and can be controlled independently or together with additional channels.
Does the series support remote sense?
Yes. The S+ and S− terminals measure voltage directly at the DUT and reduce the influence of the connecting cables.
Which dynamic modes are available?
CCD, CVD, CPD and CRD are supported, together with editable sequences, programmable current transitions and dwell times.
Can the load be controlled automatically?
Yes. LAN, SCPI, Modbus-RTU, TCP/IP and an external trigger support integration into test software and ATE systems.
How does LED mode differ from CR mode?
LED mode combines a threshold voltage Vf with a differential resistance Rd to reproduce an LED characteristic at the selected operating point.
What calibration interval is recommended?
Annual calibration is recommended for the NXI-3201.
Technical consultation and project enquiry
ET System supports the selection of the appropriate NXI-3201 model, chassis configuration and integration into automated single- or multi-channel test systems.
- Selection based on voltage, current, power and minimum operating voltage
- Planning channel count and module allocation within the NXI-F1080 chassis
- Coordination of load profiles, interfaces and test software
Send your technical requirements through the ET System contact page.
Downloads "NXI-3201"
