Automated test benches

Battery Simulator Software

Battery simulator software controls simulator hardware, runs SOC and sequence tests, triggers fault cases, and records data so BMS validation can be repeated and reviewed. Whether connecting a single battery cell simulator or orchestrating a multi-rack battery pack simulator system, the software layer determines how efficiently test engineers can build, execute, and analyze validation campaigns.

Battery simulator software dashboard for channel control, SOC curves, automation sequences, and data logging
  • Graphical interface for multi-channel control
  • SOC simulation, sequence testing, and fault steps
  • Remote interfaces such as SCPI and Modbus on supported systems

Short answer: while hardware generates the physical voltage and current, battery simulator software makes the test repeatable. It sets channel values, runs SOC or sequence tests, controls fault states where supported, and records data for review. It controls hardware modules such as battery cell simulators and pack-level test systems. Modern battery simulator software often exposes multiple control paths—a graphical upper-computer application for interactive bench work, and programmatic interfaces (SCPI, Modbus, or vendor SDKs) for automated test scripts. The software is the bridge between a test plan on paper and the thousands of data points collected during a validation run.

Core Functions

What Does the Software Manage?

Modern battery simulator software controls and monitors test cycles through four key functions that span the full BMS validation workflow, from initial channel setup through automated sequence execution to post-test data analysis.

ModelingSOC and battery simulation

Runs battery simulation functions including SOC-driven voltage profiles, pulse current steps, charge/discharge ramps, and static channel setpoints. The software translates a battery model (OCV-SOC curve, internal resistance parameters) into time-varying voltage and current commands sent to each hardware channel. On advanced systems, users can load custom OCV tables or select from pre-configured chemistry profiles for Li-ion, LiFePO4, NMC, and other cell types.

AutomationFault and sequence tests

Builds repeatable test steps for edge cases—over-voltage, under-voltage, cell imbalance, open circuit, short circuit, reverse polarity, and communication loss where supported. Sequences can branch based on measured values: for example, trigger a fault only after the BMS acknowledges a prior warning, or ramp voltage until the BMS opens its protection FETs while recording the exact trip point. This programmable fault injection replaces manual wiring changes and reduces human error.

ReportingData logging and analysis

Records channel voltage, current, temperature (where sensed), status flags, timestamps, and sequence step transitions into structured logs. Engineers compare the expected battery behavior (what the simulator was commanded to produce) against the BMS response (what the BMS measured and how it reacted). Discrepancies between these two data streams pinpoint calibration errors, threshold mismatches, or firmware bugs in the BMS under test.

Test Automation

Automating a Complete BMS Test Sequence

Manual channel adjustment is practical for quick bench checks, but production BMS validation demands automation. Below is a representative workflow for scripting a multi-cell BMS test from power-up through fault recovery.

Step 1Initialize channels

Power on all simulator channels. Configure each channel with the target cell chemistry profile, voltage limits, and current limits. Set the initial SOC for each cell—typically all cells balanced at 50% SOC for baseline testing.

Step 2Run normal operating cycle

Step through a charge/discharge profile: ramp all cells to 4.2V (Li-ion full charge), hold, then discharge to 3.0V at a defined C-rate. The BMS should balance cells during charging and trigger under-voltage protection during deep discharge. Log all BMS-reported cell voltages against simulator setpoints throughout.

Step 3Inject single-cell faults

While maintaining all other cells at nominal voltage, program one channel to simulate over-voltage (above 4.25V), then under-voltage (below 2.5V), then an open-circuit condition. Verify that the BMS detects each fault within the specified response time and takes the correct protective action—typically opening charge or discharge FETs.

Step 4Test multi-cell imbalance

Create a deliberate imbalance: set half the cells to 4.15V and the other half to 3.85V. Enable the BMS balancing function and monitor whether the reported cell voltages converge over time. Measure balancing current and compare against the BMS datasheet specifications.

Step 5Recovery and reporting

Return all channels to nominal values. Verify that the BMS re-enables charge/discharge paths after fault conditions clear. Generate a pass/fail report with timestamps for each event: fault injection, BMS detection, protection activation, and recovery. Export raw data in CSV or JSON format for traceability.

Software Architecture

Layers of Battery Simulator Software

Understanding the internal architecture helps integration engineers choose the right control path and debug communication issues. Most battery simulator software stacks follow a three-layer model.

Layer 1Communication and hardware abstraction

The lowest layer handles physical transport: TCP/IP sockets for LAN-connected simulators, serial drivers for RS485 or CAN bus interfaces, and USB HID or VISA drivers for direct PC connections. This layer translates protocol-specific packets into a uniform command/response format used by higher layers. It also manages connection health—detecting timeouts, reconnection logic, and error retry policies.

Layer 2Sequence engine and state machine

The middle layer executes test sequences. It maintains the current state of every channel, steps through user-defined sequences (ramp, hold, pulse, fault injection), and evaluates conditional branches based on measured values. A robust sequence engine handles concurrent channel operations, ensuring that a 24-cell simulator updates all channels within the required timing window for the BMS sampling rate.

Layer 3User interface and reporting

The top layer provides the graphical dashboard for interactive control and the reporting module for post-test analysis. It renders real-time channel status, plots voltage and current trends, and exports test data. On systems with programmatic APIs, this layer also exposes SCPI, Modbus, or SDK endpoints that external tools can call, treating the entire software stack as a remote-controlled instrument.

SCPI Command Reference

SCPI Commands for Battery Simulator Control

On simulators that support the Standard Commands for Programmable Instruments (SCPI) protocol over LAN or USB, test engineers can build scripts that programmatically control every channel. Below are representative SCPI command examples for common battery simulator operations.

OperationSCPI CommandDescription
Set channel voltageSOURce:VOLTage 3.700,(@1)Sets channel 1 output to 3.700 V.
Set channel current limitSOURce:CURRent 2.0,(@1)Limits channel 1 output current to 2.0 A.
Enable channel outputOUTPut:STATe ON,(@1)Turns on the output relay for channel 1.
Disable channel outputOUTPut:STATe OFF,(@1)Turns off the output relay for channel 1.
Read measured voltageMEASure:VOLTage? (@1)Queries the actual output voltage at channel 1.
Read measured currentMEASure:CURRent? (@1)Queries the actual output current at channel 1.
Set multiple channels at onceSOURce:VOLTage 3.700,(@1:12)Sets channels 1 through 12 to 3.700 V simultaneously.
Query system statusSYSTem:STATus?Returns the overall system status byte (OVP, OCP, OTP flags).
Load SOC profileSOURce:FUNCtion:SOC "Liion_NMC_3p7V",(@1)Assigns a pre-defined SOC profile to channel 1.
Trigger fault conditionSOURce:FAULt:OVERVOLTage 4.500,(@1)Simulates an over-voltage fault of 4.500 V on channel 1.
Start sequence executionSEQuence:STARt "bms_validation_v2"Starts a pre-loaded test sequence by name.
Abort sequenceSEQuence:ABORtImmediately stops the running sequence.
Reset to default state*RSTResets the instrument to power-on defaults (all channels off).

In a Python or LabVIEW automated test script, these commands are typically sent over a VISA TCP/IP socket (TCPIP::192.168.1.100::5025::SOCKET). A Python example using PyVISA:

import pyvisa
rm = pyvisa.ResourceManager()
sim = rm.open_resource('TCPIP::192.168.1.100::5025::SOCKET')
sim.write('SOURce:VOLTage 3.700,(@1)')
sim.write('OUTPut:STATe ON,(@1)')
voltage = sim.query('MEASure:VOLTage? (@1)')
print(f'Channel 1 voltage: {voltage} V')

Modbus Register Map

Modbus Register Mapping for Battery Simulators

For integration with industrial PLCs and SCADA systems, selected battery simulators expose a Modbus TCP or Modbus RTU interface. The following is a representative register map for a simulator that supports register-based control.

Register AddressTypeR/WDescriptionScale / Notes
40001HoldingR/WSystem control wordBit 0: Output enable, Bit 1: Remote mode, Bit 2: Fault reset
40002HoldingRSystem status wordBit 0: Output on, Bit 1: OVP active, Bit 2: OCP active, Bit 3: OTP active
40010-40011HoldingR/WChannel 1 voltage setpoint (float32)IEEE 754, 0.0–5.0 V
40012-40013HoldingR/WChannel 1 current limit (float32)IEEE 754, 0.0–5.0 A
40014-40015InputRChannel 1 measured voltage (float32)IEEE 754
40016-40017InputRChannel 1 measured current (float32)IEEE 754
40018HoldingR/WChannel 1 SOC setpoint0–10000 (0.00–100.00%)
40020HoldingR/WFault injection register0: None, 1: Over-voltage, 2: Under-voltage, 3: Open circuit, 4: Short circuit
40030HoldingR/WSequence control0: Stop, 1: Start, 2: Pause, 3: Resume
40031InputRSequence status0: Idle, 1: Running, 2: Paused, 3: Completed, 4: Error

For multi-channel systems, the register map repeats in blocks. For example, channel 2 voltage setpoints may start at register 40050, channel 3 at 40090, and so on. Always consult the specific simulator's communication protocol manual for the exact register layout, as offsets and scaling factors vary between battery simulator test equipment models and manufacturers.

Data Management

Data Logging and Reporting

A BMS validation run on a 24-cell simulator sampling at 10 Hz generates over 2 million data points per hour. Structured logging and efficient export formats are essential for traceable, reviewable test results.

CaptureWhat data to log

At minimum, log per-channel voltage setpoint, per-channel measured voltage, per-channel current, system status flags, sequence step number, and a UTC timestamp for every sample. For deeper analysis, also capture the BMS-reported cell voltages (read over CAN or isolated UART), temperature sensor readings, and any BMS fault codes. Comparing the simulator's commanded output against the BMS's measured input reveals gain errors, offset errors, and timing issues in the BMS analog front-end.

FormatsExport and storage formats

CSV is the most portable format—every analysis tool can read it. JSON is preferred when metadata (channel configuration, test parameters, operator ID) must travel with the data. Binary formats (HDF5, vendor-specific) are useful for high-speed logging where file size matters. Some software platforms support direct database insertion for integration with manufacturing execution systems (MES) where each battery pack's test record must be stored for regulatory compliance.

AnalysisAnalysis approaches

Post-test analysis typically involves overlaying commanded vs. measured voltage traces to identify BMS sampling errors, computing the time delta between fault injection and BMS protection response, and verifying balancing accuracy by comparing cell voltages after a balancing cycle. Automated report generation can produce a per-DUT pass/fail summary with highlighted anomalies, reducing the engineering time spent on data review from hours to minutes per test run.

Integration interfaces

Control Interfaces and Automation Paths

InterfaceBest fitTypical commands
Upper computer softwareDaily bench operation and visual control.Single-channel programming, multi-channel editing, sequence tests, and data reporting.
SCPIRemote instrument control where supported.Set channels, read values, query status, and integrate into automated benches.
ModbusIndustrial control and automation integration where supported.Exchange simulator status and commands with test systems.
LAN, RS485, CANHardware communication interfaces on selected models.Connect simulator hardware to R&D benches and automated test platforms.

Third-Party Integration

Integrating with LabVIEW, Python, and MATLAB

Battery simulator software rarely operates in isolation. Most validation labs integrate it into broader test platforms. Below are the typical integration paths for the three most common engineering environments.

LabVIEWLabVIEW integration

On simulators with SCPI support, the standard approach uses NI-VISA drivers to open a TCP/IP socket to the simulator and send SCPI commands as VISA Write/Read operations. Some vendors also provide native LabVIEW instrument drivers (`.lvlib` or `.llb` files) with pre-built VIs for channel setup, measurement, and sequence control. For simulators with Modbus interfaces, the NI Modbus Library provides Modbus master VIs that directly read and write holding registers.

PythonPython scripting

PyVISA is the standard library for SCPI-based simulators, providing a consistent API across VISA transport layers (TCP/IP, USB, GPIB). For Modbus-based systems, the `pymodbus` or `minimalmodbus` libraries handle register read/write operations. Engineers often wrap these low-level calls in a Python class that models the simulator as an object with methods like `set_cell_voltage(channel, voltage)` and `read_all_channels()`. This abstraction layer lets the same test scripts control different simulator models by swapping the backend driver.

MATLABMATLAB integration

MATLAB's Instrument Control Toolbox supports both SCPI (via `tcpclient` or `visadev` objects) and Modbus (via `modbus` object). A common pattern loads battery model parameters (OCV-SOC curves from prior characterization data) into MATLAB, computes the required voltage profile for each test step, and then streams setpoints to the simulator using SCPI write commands. Measured data is pulled back into MATLAB arrays for immediate plotting and statistical analysis without intermediate file exports.

Deployment Models

Standalone Software vs. Integrated Platform vs. Cloud Control

The software environment for battery simulation falls into three deployment models, each with different trade-offs for BMS validation labs.

Deployment modelArchitectureBest forLimitations
Standalone upper-computer softwareWindows application installed on a dedicated PC connected directly to the simulator via LAN, USB, or RS485.Single-bench R&D labs where one engineer controls one simulator. Quick setup, no network dependencies.No centralized data management. Each PC maintains its own test sequences and logs. Scaling to multiple simulators requires duplicating the setup.
Integrated test platformThe simulator software runs as a module within a larger test automation framework (e.g., NI TestStand, Vector CANoe, custom Python orchestration layer).Production validation lines where the simulator must coordinate with other instruments—environmental chambers, CAN loggers, HIL systems, and MES databases.Higher integration effort upfront. Requires clear API documentation and error-handling conventions from the simulator vendor.
Cloud-based or remote controlThe simulator connects to a local gateway PC that bridges to a cloud platform via MQTT or REST APIs. Engineers access dashboards and run tests through a web browser.Distributed teams or multi-site operations where test data must be accessible across locations. Enables remote monitoring of long-duration life-cycle tests.Network latency can affect real-time control loops. Security considerations increase. Internet connectivity dependency is a risk for 24/7 test cells.

Security

Security Considerations for Remote Battery Simulator Control

As battery test labs adopt networked simulators and cloud-based dashboards, the attack surface grows. A compromised simulator could inject false voltage readings into a BMS validation run, mask real faults, or damage connected hardware through unauthorized commands.

Network segmentationIsolate simulator networks

Place battery simulators and their control PCs on a dedicated VLAN or physically separate network segment. Do not expose simulator control ports (SCPI port 5025, Modbus port 502) to the corporate LAN or the internet without an authenticated gateway.

AuthenticationRestrict access at the transport layer

Where supported, configure IP whitelisting on the simulator so only authorized control PCs can send commands. For remote access, use SSH tunnels or VPN connections rather than direct port forwarding. Certificate-based authentication provides stronger protection than shared passwords.

Audit loggingLog all control commands

Enable the software's command logging feature to record every voltage change, sequence start/stop, and fault injection event with timestamps and source IP addresses. Audit logs provide forensic evidence if a test result is questioned and help detect unauthorized access attempts.

Firmware updatesKeep firmware current

Simulator firmware updates often patch security vulnerabilities in the embedded TCP/IP stack or web server. Maintain a firmware update schedule as part of lab asset management. Verify the integrity of firmware files using vendor-provided checksums before applying updates.

FaithTech features

FaithTech Software Environment

Multi-channel GUIVisual channel control

Control single channels or edit multiple channels simultaneously for BMS validation workflows. The graphical interface provides real-time voltage and current readback, color-coded status indicators per channel, and drag-and-drop sequence editing for building test procedures without writing code.

SOC simulationBattery simulation functions

Use battery simulation, charge/discharge, pulse, sequence, and SOC-related functions on supported systems. FaithTech's simulation engine supports user-defined OCV-SOC tables, configurable internal resistance models, and temperature-dependent voltage compensation for accurate battery behavior replication.

ReportingData reporting and analysis

Use professional testing software to support data reporting and engineering analysis. Export test data in CSV, JSON, or binary formats with automatic report generation that includes pass/fail summaries, waveform plots, and statistical comparisons between commanded and measured values.

FAQ

Battery Simulator Software FAQ

What does battery simulator software control?

It controls channel settings, battery simulation functions, sequence tests, pulse steps, fault states where supported, and data reporting. The software translates engineering requirements into hardware commands that set voltages, currents, and timing for each simulator channel.

Does FaithTech support remote control interfaces?

Selected FaithTech battery simulator models support interfaces such as LAN, RS485, CAN, SCPI, and Modbus. Confirm the exact interface for the target model. For automated test benches, SCPI over LAN is the most common remote control path, while Modbus is preferred for industrial PLC integration.

Is battery simulator software a standalone product?

Usually no. It is best understood as the control and automation environment for battery simulator hardware and test benches. The software is typically bundled with the hardware purchase, though some vendors offer SDKs and API libraries as separate downloads for custom integration projects.

What should I confirm before integration?

Confirm the simulator model, required communication interface, automation language, data reporting needs, fault cases, and whether the setup must integrate with a larger BMS test bench. Also verify the software's maximum channel count, sampling rate, and whether it supports the specific battery simulator fundamentals relevant to your chemistry and pack configuration.

What operating systems does battery simulator software support?

Most battery simulator upper-computer software runs on Windows (Windows 10/11). Some vendors provide Linux support, typically through cross-platform frameworks like Qt or through web-based interfaces that are OS-agnostic. For programmatic control with Python or MATLAB, operating system compatibility is usually determined by the VISA or Modbus library, both of which are multi-platform. Always confirm OS support for your target simulator model before procurement, especially for automated production lines that may run on Linux-based test controllers.

How do I protect test data when controlling a battery simulator remotely?

Use encrypted communication channels such as SSH-tunneled VISA connections or VPNs for remote SCPI access. Isolate the simulator control network from the corporate IT network using a dedicated VLAN or physical segmentation. Restrict access by IP whitelist or certificate-based authentication where the simulator supports it. Enable command audit logging to track every voltage change and sequence operation. Keep simulator firmware updated to patch vulnerabilities in embedded network stacks. For cloud-connected setups, verify that the cloud platform encrypts data both in transit (TLS 1.2+) and at rest.

Related guides

Related Emulation Topics

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