How to Cascade Acute Oscilloscopes for More Synchronized Analog Channels

Important: Cascading Applies to Analog (DSO) Channels Only

A common misconception is that Acute logic analyzers can be cascaded for higher digital channel counts. They cannot. Only the oscilloscope (DSO) functionality of Acute instruments supports multi-unit cascading. This means:

TravelScope (pure PC-based oscilloscopes) — supported
MSO3000 series — only the analog scope channels of MSO units can be cascaded; the digital logic analyzer channels do not cascade
TravelLogic, LA4000, and other pure logic analyzers — do not support cascading

If you need more digital channels than a single Acute logic analyzer provides, the correct path is to choose a higher-channel-count single unit (e.g., LA4136E/B at 136 channels) rather than attempting to cascade smaller units.

When You Need Cascading

A single Acute oscilloscope provides up to 4 analog channels. For most bench debugging this is plenty, but several scenarios demand more synchronized analog channels than one instrument offers:

Multi-rail power validation: A modern SoC can have 8+ independent power rails, each with its own ramp, sequencing, and ripple characteristics. Capturing all rails simultaneously during a boot sequence requires more than 4 analog channels with sample-accurate alignment.
Multi-clock domain analysis: Verifying skew between several clock signals (e.g., DDR DQS strobes, reference clocks, recovered clocks) requires simultaneous analog capture on every clock to measure phase relationships.
Differential signal pair characterization: Analyzing multiple high-speed differential pairs (P/N) for skew and crosstalk benefits from one channel per signal across the pair group.
Cross-board debug: Comparing signal behavior across multiple boards in a system (e.g., backplane slots) without moving probes between captures.

Cascading combines multiple Acute oscilloscopes into a single synchronized instrument exposing all analog channels under one software interface, with one shared sample clock and one trigger reference.

Hardware Setup

What You Need

Two or more Acute oscilloscopes (TravelScope or MSO3000 series — models can be mixed within the same family)
One cascade cable per additional unit (BNC-to-BNC, supplied with the instruments)
A USB connection from each unit to the host PC, ideally via a powered USB 3.0 hub

Physical Connections

Designate a master unit. The master generates the sample clock and trigger reference distributed to all other units. Choose the unit physically closest to your trigger source.
Connect cascade cables. Each Acute oscilloscope has CASCADE OUT and CASCADE IN BNC connectors on the rear panel. Run the master’s CASCADE OUT to the first slave’s CASCADE IN. Daisy-chain additional slaves: first slave’s CASCADE OUT to second slave’s CASCADE IN, and so on.
Keep cascade cables short and matched. Use the supplied cables (typically 30 cm). Longer or unmatched cables introduce propagation delay that degrades inter-unit timing alignment.
Connect probes. Attach analog probes from each unit to the signals of interest. Confirm that all probe ground leads return to the same ground reference on the target board to avoid ground-loop artifacts in the analog measurement.
Connect USB. Each unit needs its own USB connection to the host PC. Use USB 3.0 ports (or a powered USB 3.0 hub) for fastest data transfer during long captures.

Note for MSO3000 users: Cascading distributes the analog scope clock and trigger across units. The digital logic analyzer channels on each MSO3000 continue to operate independently per unit and are not combined across the cascade. Only the analog scope channels appear in the unified cascade view.

Software Configuration

Step 1: Launch and Detect Units

Open the Acute software. Navigate to Device > Cascade Setup. The software automatically enumerates all connected Acute oscilloscopes. You should see each unit listed by serial number and model.

Step 2: Assign Master and Slaves

Select one unit as the master. The remaining units are automatically assigned as slaves. The master’s sample clock is distributed to all slaves through the cascade cable, ensuring all units sample synchronously.

Step 3: Configure the Unified Analog Channel Map

The software presents a single analog channel map across all units. Channels are numbered sequentially: the master’s analog channels appear first, followed by each slave’s analog channels in cascade order. You can rename channels and assign them to display groups just as you would with a single unit.

For MSO3000 cascades, the LA channels of each unit remain available in their respective per-unit views but are not part of the cascaded channel map.

Step 4: Set Sample Rate, Vertical Settings, and Memory Depth

All cascaded units operate at the same sample rate, configured on the master. Vertical settings (range, offset, coupling, bandwidth limit, probe attenuation) are configured per channel as usual. Memory depth per channel is determined by each unit’s local memory; the software handles aggregation transparently.

Step 5: Configure the Trigger

The trigger is defined on the master and distributed to all slaves over the cascade cable. You can trigger on any analog channel across any unit in the cascade. Available trigger types in cascade mode:

Edge on any single analog channel
Pulse width / runt / window on any single analog channel
External via the master’s EXT TRIG input

For more complex cross-instrument triggering (e.g., a pattern across both an analog rail event and a separate digital signal on a target), use a target-side combinational signal driven into the master’s EXT TRIG input.

Timing Alignment Verification

Before running your real measurement, verify that the cascade is properly synchronized:

Apply a common test signal to one analog channel on each unit — a 1 MHz square wave from a function generator works well, split with a BNC T or a low-skew distribution amplifier.
Capture the signal at your intended sample rate.
Measure edge-to-edge skew between units using the software’s cursor measurement tools. Skew should be less than one sample period.
If skew exceeds one sample period, check that all cascade cables are the supplied length and properly seated. The software’s Cascade Delay Compensation setting (under Device > Cascade Setup > Advanced) lets you apply per-unit delay offsets to correct for residual cable propagation differences.

Practical Tips

Label everything. With multiple units and 8+ analog channels in play, probe identification matters. Use colored tape on probe leads and keep a simple spreadsheet mapping signals to channel numbers.

Use a powered USB hub. Multiple oscilloscopes drawing bus power can exceed a host PC’s USB current budget. A hub with per-port power delivery rated for at least 500 mA/port avoids intermittent disconnects mid-capture.

Start with two units. Validate cascade timing alignment with two units before adding more. Most cabling and configuration mistakes are easier to diagnose with a smaller setup.

Save cascade configurations. The Acute software lets you save the entire cascade setup (channel map, vertical settings, trigger, display groups) as a configuration file. Save and version-control these alongside your hardware design files for repeatable debug sessions.

Mind thermal load. Multiple oscilloscopes operating continuously generate heat. Ensure adequate ventilation, particularly in rack-mounted test setups.

Practical Example: 8-Channel Power Rail Validation

A typical SoC bring-up board has 8 power rails that must come up in a specific sequence. With two cascaded TravelScope units (4 analog channels each):

Assign rails 1–4 to the master unit, rails 5–8 to the slave.
Configure the master’s trigger as edge-rising on the system EN signal (or PG of the first rail).
Set both units to capture 50 ms with 10% pre-trigger to see the full ramp profile.
After capture, the unified view shows all 8 rails on a common time base, letting you measure ramp time, sequencing order, and inter-rail delays directly.

This is the kind of measurement that would otherwise require either an 8-channel benchtop oscilloscope (an order of magnitude more expensive) or sequential captures that cannot reveal true sequencing relationships.

Summary

Cascading Acute oscilloscopes is straightforward: connect cascade cables, assign master/slave roles in software, configure a unified analog channel map, and verify timing alignment. The cascade cable distributes the master’s sample clock and trigger to maintain sample-accurate synchronization across all units. Cascading applies only to the analog (DSO) channels — Acute logic analyzers and the LA channels of MSO instruments do not cascade. With proper alignment verification and probe management, cascaded oscilloscope systems give you the analog channel density needed for multi-rail power validation, multi-clock characterization, and cross-board debug without stepping up to a much more expensive benchtop instrument.