4-Channel Power Measurement Conditioner: A Domestic Alternative to NI

The Case for a Domestic Power Measurement Signal Conditioner

In industrial test and measurement environments, accurate power analysis depends on far more than a capable DAQ card. The signal conditioning layer between the physical world and the acquisition hardware is where measurement quality is often won or lost — particularly when dealing with high-voltage, high-current systems that cannot be fed directly into standard I/O modules. National Instruments (NI) has long been the default choice for this class of hardware, but rising demand for supply-chain independence and lower total system cost has pushed Chinese manufacturers to develop credible domestic alternatives. The RM-26999 from Shenzhen Xinmai (Sienovo) is one such product: a rack-mount signal conditioning unit purpose-built for multi-channel power measurement, designed to slot into NI-compatible measurement architectures without sacrificing accuracy or channel synchronization.

What the RM-26999 Does

The RM-26999 is a rack-mount signal conditioning device intended to sit between a power bus under test and a multifunction I/O DAQ backend. Its role is to scale, isolate, and condition raw electrical signals before they reach the digitizer — protecting expensive acquisition hardware and ensuring that the voltage and current waveforms delivered to the ADC inputs are within a safe, linear range.

The device supports four voltage input channels with a peak voltage rating of up to 2000 V. This range covers a wide span of industrial and EV powertrain test scenarios, including three-phase grid measurements and high-voltage battery pack characterization, where bus voltages can exceed 800 V in modern electric vehicle platforms.

For current measurement, the RM-26999 provides four dedicated current sensor ports. Critically, these ports are optimized for fluxgate sensors rather than simpler Hall-effect or shunt-based solutions.

Why Fluxgate Sensor Optimization Matters

Fluxgate current sensors operate on a fundamentally different principle than resistive shunts or open-loop Hall sensors. A fluxgate core is driven into saturation in alternating directions; the asymmetry introduced by an external DC or low-frequency AC field is detected and used to null the field via a feedback winding, yielding a closed-loop measurement. The result is exceptional DC accuracy, very low offset drift, and high bandwidth — properties that matter enormously when measuring the switching current waveforms produced by power inverters or the slowly varying charge/discharge currents of large battery cells.

Supporting a fluxgate sensor correctly requires the conditioning hardware to supply a stable excitation current to the sensor drive coil, manage the bidirectional feedback loop, and present a clean signal line back to the acquisition system. The RM-26999 provides the dedicated power, communication, and signal lines that fluxgate sensors require — a detail that distinguishes it from generic sensor input modules that only passively accept a voltage or current output.

Integration with Synchronous Multifunction I/O

A key design goal of the RM-26999 is its ability to connect to multiple synchronous sampling multifunction I/O devices. Power measurement accuracy over multiple phases requires that voltage and current channels be sampled at exactly the same instant; any skew between channels introduces phase error that directly corrupts power factor and reactive power calculations. By conditioning all four voltage and four current channels within a single rack-mount unit and routing synchronized outputs to a compatible DAQ backend, the RM-26999 keeps the timing architecture clean.

This makes it suitable as a front-end for NI CompactDAQ or PXI-based acquisition systems — and by extension, for compatible domestic DAQ platforms that implement the same interface standards.

Positioning as a Domestic NI Alternative

NI's equivalent signal conditioning products for high-voltage power measurement — such as modules in the NI-9200 series or dedicated power analysis front-ends — carry significant cost premiums and are subject to export control considerations that have become increasingly relevant for Chinese industrial customers. Shenzhen Xinmai positions the RM-26999 explicitly as a domestically produced substitute, offering the same measurement architecture at a price point and supply-chain profile better suited to volume industrial deployment within China.

Sienovo provides NI-localization customization services, meaning the RM-26999 can be tailored to specific channel configurations, form factors, or interface requirements for customers who are migrating existing NI-based test systems to domestic hardware.

Typical Application Scenarios

• EV powertrain and battery testing: High-voltage bus measurement up to 2000 V pk combined with fluxgate current sensing covers the full operating envelope of modern traction battery packs.
• Three-phase motor drive characterization: Simultaneous four-channel voltage and current acquisition enables real-time calculation of per-phase and total power, power factor, and harmonic content.
• Grid-tie inverter validation: Accurate measurement of both fundamental and switching-frequency components requires the bandwidth and low-offset performance that fluxgate-based current sensing provides.
• Industrial power quality monitoring: Rack-mount form factor and synchronous multi-channel design fit naturally into 19-inch test rack infrastructure.

For teams evaluating a transition away from NI hardware for power measurement applications, the RM-26999 represents a technically coherent starting point — preserving the core measurement architecture while reducing dependency on foreign supply chains.