CDJ-2000nx2 test

[trickofdjequip]

Hello.
Today I tested cdj-2000nx2 and cdj-3000. They were on the same local network. 3000 worked perfectly. The CDJ2000nx2 had problems like this:

Pro DJ Link: CDJs fail to send absolute position data (abspos packets) to STC. Timecode updates at ~5Hz instead of 67Hz, producing visible stuttering. Keepalive and status packets may still arrive, making the connection appear partially functional.

Also when I inserted a flash drive into CDJ2000nx2, the metadata wasn't transferred correctly. The track was simply called "track #~." The waveform wasn't displayed. When flash drive insert into CDJ3000, I'm play through "Link" on CDJ-2000nx2. In this case metadata and waveform transferred correctly, but problem described above has not gone away.

[fiverecords]

STC was developed and tested on CDJ-3000, so CDJ-2000NXS2 behavior hasn't been fully verified.

The 5Hz stuttering means the NXS2 isn't sending absolute position packets to STC — it likely handles the handshake differently than CDJ-3000. The metadata issue is probably related too — the NXS2's dbserver may need a connection sequence that STC doesn't perform because CDJ-3000 doesn't require it.

If you're able to do a Wireshark capture of the network traffic with the NXS2 connected (even just 10-20 seconds of it loading a track and playing), that would be incredibly helpful. It would let me see exactly what the NXS2 expects vs what CDJ-3000 does. You can attach the .pcapng file to the GitHub issue.

[trickofdjequip]

cdj test.zip

[fiverecords]

What operating system do you use?

[trickofdjequip]

MacOs 15.7.4 mbp m3pro

[fiverecords]

Ok, I’m going to prepare a beta so you can test it.

[trickofdjequip]

I’m going to prepare a beta so you can test it. -- thank you so much. I'm also can test it on windows 10 laptop.

Can I ask for one feature that is not related to the request issue?
So, I can export my collection from rekordbox like .xml file. This file contains metadata.
It would be great if I could export this file to a track map editor to get a tracklist with the metadata already written in.

test.xml - this is example file, exported from rekordbox.

[fiverecords]

Here's the 1.8.3-beta. Two things in this build:

1. CDJ-2000NXS2 support — smooth timecode from beat-derived position (interpolated between 5Hz status packets + beat packets), and metadata queries adapted for NXS2 dbserver (uses player 1-4 instead of 5). Mixed networks (NXS2 + CDJ-3000) should work simultaneously.

2. rekordbox XML import — in the TrackMap Editor, the Import button now accepts .xml files exported from rekordbox (File → Export Collection in xml format). It imports artist, title and duration for each track. Artwork, waveform and cue points will populate automatically the first time each track plays on a CDJ.

If you get a chance to try it on Windows 10/11 as well, that would be great. Let me know how it goes — especially whether metadata (artist/title/artwork) resolves correctly on the NXS2, and if the timecode output looks smooth.

STC -1.8.3-Beta-Win.zip

STC -1.8.3-Beta-Mac.zip

[trickofdjequip]

Ok, I try it tomorrow. If I found issues - send you WireShark report.

[trickofdjequip]

So it works correctly on macos and win10.

I'm found any features:

1. 2 computer with STC can't be in one local network. MacOS app make crash, win app don't take metadata and tc stutter. This is file with logs of crash stc183 crash.pcapng.zip.

2. While I change load tracks fast - metadata may take a long time to load. I think it flash drive speed problem. But send you logs load new tracks cdj2000.pcapng.zip.

3. May be you can add "clear all" button in track map window.

4. Now when I write offsets I need to press "save" button. May be use for this case hotkey like "return/enter"?

5. Windows app don't take a waveform

Big thanks for your app!

[fiverecords]

Great news that it works on both macOS and Win10!

1. Two computers with STC on the same network — this is expected. Pro DJ Link only supports one bridge application per network. Both STC instances announce as player 5 on the same ports, so they compete for packets. The Mac crashes because macOS distributes incoming packets between the two apps (SO_REUSEPORT). The Windows side doesn't crash but gets incomplete data — metadata fails and timecode stutters because the other STC is stealing part of the traffic. With only one STC running, everything works. This is a protocol limitation, not a bug.

2. Slow metadata when changing tracks fast — I checked your capture. This is the existing two-phase metadata pipeline: each track needs ~6 seconds for full data (phase 1: metadata + artwork, phase 2: waveform + beat grid + cues), and queries are serialized ~3 seconds apart. When you switch tracks faster than that, the new track waits in queue behind the previous track's phase 2. Not related to NXS2 or USB speed — same behavior on CDJ-3000. I'll look into skipping pending phase 2 when the track changes, but that's a future optimization.

3. Clear All button — noted, will add.

4. Enter/Return to save offset — noted, will add.

5. Windows not showing waveform — could you check if Windows Firewall is blocking STC? The waveform data comes via NFS (UDP), which Windows Firewall may block while the metadata (TCP) gets through. That would explain why metadata works but waveform doesn't. If you can send a Wireshark capture from the Windows machine, I can confirm.

Thanks for the thorough testing!

[trickofdjequip]

cdj2000 metadata.pcapng.zip file from windows machine

[fiverecords]

I checked the Windows capture in detail. STC never opens a TCP connection to the CDJ — not even a single attempt in 28 seconds. The NXS2 status packets arrive fine (UDP works), but all metadata and waveform data needs TCP.

Two things to try:

1. Restart STC — if the previous test with both computers left stale data in the cache, STC may think it already has the metadata and skip the request.

2. Check Windows Firewall — go to Settings → Firewall & network protection → Allow an app through firewall → find STC and enable both Private and Public. The firewall rule is tied to the specific .exe path, so a new install or beta build may need a fresh rule. You can also try temporarily disabling the firewall to confirm.

The CDJ-3000 in your capture had no track loaded — that's fine, the NXS2 loads from its own USB and the metadata request goes directly to the NXS2. The code path is correct.

If it still doesn't work after those two steps, let me know and I'll add debug logging to the dbserver connection to trace exactly where it gets stuck.

[trickofdjequip]

Restart STC
It's quite a shame, but restarting helped.

[fiverecords]

No worries, that can happen when the cache has stale data from a previous session. Glad a restart fixed it.

I'm preparing a new beta with the improvements — faster metadata loading, Clear All button, and Enter to save. I'll send it shortly.

[trickofdjequip]

And I found next issue: MTC output stutters. Connected throught din5 cable. LTC output work correctly.

IMG_5308.MOV