CSL have released the Signal Analyser 2, the updated successor to the CS2389 that many IoT installers have carried for years. It is a better device than its predecessor. Cleaner interface, faster reporting, multi-network survey in one pass. For alarm and fire installers doing 2G/4G work, it does what it says.
But spend five minutes with the spec sheet and three limitations jump out immediately. Limitations that matter if you are installing routers rather than alarm panels, and especially if those routers are 5G.
It Still Only Tests 2G and 4G
CSL’s own product page is clear on this. The Signal Analyser 2 “works seamlessly across 2G and 4G networks.” That is the full list. There is no 5G support.
This has been the story with the CS2389 since it launched, and it remains the story with its replacement. CSL’s customer base is heavily weighted toward the alarm signalling market, where 4G is the ceiling for most deployments. For that use case, 4G-only testing is probably fine.
For IoT router installers in 2026, it is not fine. If you are commissioning a Teltonika RUTX50, a Peplink, or any 5G NSA router, you need to know what the 5G signal actually looks like at that site. You need RSRP on n78, SINR on the 5G carrier, and whether the site is worth locking to 5G or leaving on a strong B3. The Signal Analyser 2 cannot tell you any of that.
You Now Need a Phone to Use It Properly
The original CS2389 was a standalone device. You switched it on, ran a scan, read the results on the screen. Simple.
The Signal Analyser 2 is designed to work alongside CSL’s My Base App. The device has become part of a two-piece kit: the hardware you carry plus the phone you already have in your pocket.
This might seem minor. But think about what it means on a practical level. You now have two things to keep charged, two things that need to be working together, and a reporting workflow that depends on your phone being present and the app being up to date. The original appeal of a dedicated signal tester was precisely that it was self-contained. The Signal Analyser 2 chips away at that.
It Is Still a Separate Device You Have to Buy, Carry and Maintain
The CS2389 retails at around £400 to £640 depending on where you buy it. The Signal Analyser 2 will be priced in the same bracket.
That is a capital purchase for a piece of equipment that has one job: tell you what networks are available before you install the router. It sits in your bag, it needs charging, it needs firmware updates, and if it gets dropped or lost, it needs replacing.
All of this to test a device that is already on site and already knows everything about its own signal.
The Installer Already Has Everything They Need
The router you are commissioning contains a fully capable cellular radio. It knows its RSRP, RSRQ, SINR, RSSI and CQI across every technology it supports, including 5G NSA. It knows which operator it is registered to, which band it is on, and what the ARFCN is. It can be instructed to lock to a specific band, register to a specific operator, and run a speed test.
The only thing missing has been a proper interface to access all of that from a browser, without needing to understand AT commands or SSH.
That is exactly what CellTester does.
What CellTester Gives You Instead
CellTester runs in your browser. You connect your laptop to the router on site, open the tool, enter the router’s IP and credentials, and hit commission. From that point, the router tests itself.
Full 5G NSA support. If the router can see n78, you see n78. RSRP, RSRQ, SINR, RSSI on the live 5G carrier, not a proxy reading from a separate device that does not support 5G at all.
Operator sweep. CellTester locks to each UK network in turn, waits for registration, reads signal metrics, and runs a speed test per operator. You end up with a ranked comparison of EE, Vodafone, Three and O2 at that exact location, tested on the actual device, not on a separate radio module with different antenna characteristics.
Band scan. Lock to each band individually, test it, move to the next. At the end you know exactly which band delivers the best throughput at that site, and you can lock the router to it in the same session.
4×4 MIMO antenna analysis. On the RUTX50 and other MIMO-capable routers, CellTester shows RSRP per antenna port. You can see whether all four ports are contributing or whether two of them are barely receiving anything. That tells you whether the antenna placement is working, which no handheld tester can do.
Commissioning report. At the end of the session, CellTester generates a downloadable PDF certificate: site name, router details, operator results, band results, recommended configuration. Something you can hand to the end customer or keep on file.
No extra hardware. You already have a laptop. You are already connected to the router. There is nothing else to buy, charge or carry.
The Honest Comparison
| CSL Signal Analyser 2 | CellTester | |
|---|---|---|
| 5G NSA support | No | Yes |
| Tests the actual install router | No | Yes |
| Operator sweep with speed test | No | Yes |
| Band scan with speed test | No | Yes |
| 4×4 MIMO antenna analysis | No | Yes |
| Commissioning report | Basic export | Full PDF cert |
| Requires separate hardware | Yes (£400+) | No |
| Requires phone app | Yes | No |
| Works in browser | No | Yes |
The Signal Analyser 2 is a good tool for alarm installers who need a quick 4G site survey before fitting a DualCom. It is not the right tool for IoT router commissioning in 2026.
Try CellTester
If you are commissioning Teltonika, Peplink, Robustel or any other router that already runs on your laptop network, try CellTester. Your install kit is your test kit.