Keysight 34980A vs N6700B: A Practical Buyer's Comparison of Modular Test Systems

Before the Comparison: What Are These Keysight Systems?

I'm the office administrator for a 58-person engineering company. I manage all test equipment buying—roughly $250,000 a year across 11 vendors. I report to both operations and finance. That means I don't design test benches, but I do see the invoices, the calibration bills, and the delivery delays. I'm also the one who has to explain why a 'system' ended up costing more than the number finance approved.

When I first started in this role, I assumed 'modular system' meant one flexible chassis that could do most things. That was my initial misjudgment. The truth is, a modular system is only as useful as the modules you choose. And the two Keysight systems I want to compare are built for very different jobs.

What Is Keysight Inc.?

Keysight Technologies Inc. is a test and measurement company that was spun out of Agilent in 2014. It makes signal generators, spectrum analyzers, multimeters, power supplies, oscilloscopes, and network analyzers. The Keysight 34980A and the Keysight N6700B both come from that catalog, and both are called 'systems.' That's where the confusion starts.

If you searched 'what is inc' and landed here, the short answer is that 'Inc.' is simply the abbreviation for 'incorporated.' Keysight Technologies Inc. is an independent, publicly traded corporation.

The Main Difference: One Measures, One Powers

The Keysight 34980A is a Multifunction Switch/Measure Unit. The Keysight N6700B is a Modular Power System mainframe. In plain English, the 34980A routes signals and makes measurements. The N6700B provides clean, programmable DC power and measures what the device under test draws.

I'll give you the procurement translation: the 34980A is like a switching room with a built-in quality inspector. The N6700B is like a set of programmable power taps with readback. If you confuse the two, you'll order the wrong chassis and discover it when your modules don't fit your application.

Dimension 1: Module Ecosystems

Both mainframes are modular, but their modules are not interchangeable. The 34980A has eight slots for switch/measure modules: multiplexers, matrices, RF switches, digital I/O, and D/A converters. The internal DMM option is what makes it a measurement system rather than a switch box. The N6700B has four slots for DC power modules with different voltage, current, and accuracy levels.

Conclusion for this dimension: The 34980A is the better fit when you need to connect many signals to one measuring engine. The N6700B is the better fit when you need multiple programmable power rails. There is no universal winner here. There is only the module ecosystem that matches your test plan.

Dimension 2: Built-In Measurement Capability

The 34980A can be configured with an internal 6.5-digit DMM. That's a big deal for purchasing because it can replace a separate bench multimeter. With scanning modules, it can step through dozens of channels and log data over time. From my seat, that means one box, one power cord, one calibration item instead of a stack of separate instruments.

The N6700B is different. It reads back voltage and current on each power module, and certain modules can handle dynamic loads and transients. But it is not a general-purpose measurement unit. If someone tells you they need 'a Keysight N6700B' to measure temperature sensors, that's a red flag. They probably need the 34980A.

Here is the surprising part for me: I assumed the 'power system' would be the more versatile tool. In practice, the 34980A replaced two separate instruments on one bench and made the lab easier to manage. The N6700B solved a different problem—power sequencing—but it did not reduce equipment clutter in the same way.

Dimension 3: Software, Control, and 7.1 Systems Test Setups

Both systems are programmable. You can control them over LAN, USB, or GPIB with SCPI commands. For automated test systems, that's the real requirement. If a chassis can't talk to your existing software, the specs don't matter.

One search phrase that brings people here is '7.1 systems.' In our lab, that phrase showed up when a customer asked us to verify power sequencing on a 7.1-channel audio receiver. The N6700B was the right system because it gave us four independent rails, and we could turn them on in sequence under software control. For a 7.1 systems project, that's often exactly what you need—multiple supplies, controlled startup, and current readback on each rail.

If your project is more about signal routing and data acquisition, the 34980A's scan lists are a better fit. I'm not going to claim one interface is easier; I've seen teams get comfortable with either. But the question to ask is: which system does your test software already support?

Dimension 4: Rack Space and Bench Layout

The N6700B is the more compact mainframe. It's designed to fit into tight rack space. The 34980A is a larger chassis because it carries eight module slots plus the measurement engine. I don't quote exact rack units from memory—that changes with handles and options—but in our lab the N6700B freed up enough room to mount a signal generator in the same rack. The 34980A needed more vertical space, yet it still did the work of two or three instruments.

Conclusion: If rack space is your only constraint, the N6700B wins. If you're building a rack that would otherwise contain a separate switch, DMM, and data logger, the 34980A may still be the lower-space solution overall.

Dimension 5: Purchasing and Total Cost Reality

From an admin buyer perspective, list price is the beginning, not the end.

• 34980A: The mainframe plus DMM option is a meaningful upfront purchase. But if it replaces a separate switch, DMM, and logger, the total cost can be lower. Calibration is simpler because it's one mainframe with one internal DMM.
• N6700B: The mainframe price may look more approachable. The modules are where the cost accumulates. If you need four high-precision modules, the total can approach the 34980A price. Ask for module costs separately before approving a budget.

Looking back, I should have asked about calibration costs before our first N6700B order. At the time, I focused on the mainframe quote and forgot that each module may have its own calibration cycle. That created a change request and a delay. Not a huge disaster, but the kind of mistake that makes finance ask questions.

Even after we chose the 34980A for a data acquisition application, I kept second-guessing. What if the modular format made service more complicated? The first calibration bill settled it: one box, one report. I relaxed after that.

Scenario-Based Recommendation

I don't like 'buy A not B' conclusions, because I've seen too many good purchases go into the wrong environment.

• Pick the Keysight 34980A if you're dealing with many signals, logging data, switching between sensors, or replacing a bench full of separate switches and multimeters. It's the better measurement system.
• Pick the Keysight N6700B if you're powering multiple rails on a prototype, testing power supplies, validating DC-DC converters, or building a power-sequencing setup—like a 7.1 systems audio board with several supply voltages.

A product rep who says 'this is not the right system for your application' is more credible than one who forces a square peg into a round hole. That honesty matters when you're spending a serious equipment budget.

The Bottom Line (With a Caveat)

The Keysight 34980A and Keysight N6700B are both excellent modular systems from a well-known manufacturer. They are not competitors to each other; they are different tools. The right choice depends on whether you're measuring signals or supplying power—and on what your automation software expects.

This worked for us, but our situation is a mid-size engineering services lab. If you're in high-volume production, semiconductor research, or ruggedized defense, my experience may not transfer. I've only worked with roughly 30 Keysight purchases. Check the current product pages or ask Keysight directly before you commit. That's not me being evasive; it's me being honest about the boundary of my viewpoint.