Canon 600EX II-RT drops link- HELP!

[Phillyphoto]

Scenarios I have tried: 

Using Canon Transmitter ST-E3-RT as the master and (2) 600 EX II-RTs as slaves.

Using A 600EX as master and B 600EX as slave.

Using B 600EX as master and A 600EX as slave. 

I get the same result of the slave dropping link. The time varies. Sometimes it drops link in 4 mins, sometimes 10mins, sometimes 20 or more minutes. The only way to relink them is by turning everything off and back on.

All channels are the same. Yes, I have scanned for the best connection as well as every other channel and AUTO.

All IDs are the same. 

Not near a wifi-router or airport, I'm in a row home in Philadelphia. 

Using NiMh rechargeables and using freshly charged batteries for every test. Batteries are about 2 years old. 

I have spoken to 2 Canon service reps and neither of them has any idea what the problem is. I really don't have the money to spend on sending everything in for "repair". 

Any help is greatly appreciated, thanks!

[eschrad]

I just wanted to share that I shot a wedding last month... this one indoors... and with my flashes setup according to my previously explained possible solution, I didn't have any connection issues.  The wedding was in a downtown area... the ceremony in a first floor event space and the reception in a top floor event space... and I was able to remotely fire my speedlights with no dropped connections.  There was also a DJ at the reception, which can often be a source of interference.  I know a lot of people have posted since my original post that even with the manually set flash ID numbers, they are still having problems.  But I just wanted to chime in that so far the solution seems to be working for me.

[halocastle]

As someone who was experiencing dropped links on a regular basis, I believe my issue has been resolved (at least to my satisfaction). As I’ve indicated in another post (above), I read forums of other 2.4 GHZ triggers (Godox, etc.) and came to the conclusion that RF interface in the channels was causing drops. So I used a Wi-Fi analyzer for Android phones (WiFiman is free, good and ad free) and saw interference where the RT scan didn’t. I set the channel manually and my drops almost disappeared – almost (from 1 to 2 every 30 minutes to 0 to 1 every two hours).

I now use channel 15.

But then I got to thinking about the ID because I was using a custom one (0333). In other systems that have IDs – so you can “uniqueify” your setup – you have at most 100 to chose from (0-99, typically). But Canon’s RT system has 10,000 – 0000 to 9999. That’s a lot of IDs! And each ID must have a unique radio frequency assigned to it. Speculating, I think that the gap between frequencies is tiny and, therefore, the fault tolerance low: RF interference is far more likely to affect these IDs than the channels. So I set my ID to 0000 and repeated the test and had zero drops in two hours. I ran the test again using 9999 and once again had zero drops in two hours. I believe using the extremes of the ID range bookends the fault to just one direction, up only (if using 0000) or down only (if using 9999). If this is true, this single change may reduce drops by 50%!

I now use ID 9999.

Since making these changes, testing for hours yesterday (and even today), I have not experienced a single drop. My 430s x 4 have gone to sleep (1 hour setting) and awakened successfully (using the ST-E3-RT (v1)), ran out of juice (FYI: I’m using rechargeables), or lost – and regained – link.

I’m happy.

As for Canon, there’s really not much they can do, except maybe reduce the number of IDs (why 10,000?). When they created the RT system (2012), there was a lot less interference and the FCC mandates that devices must accept any interference received, including interference that may cause undesired operation. And rest assured that the “others” have drops and misfires as well so changing to another 2.4 GHZ trigger system isn't really, “The Solution.”

[zachary-ap]

I also found that using the suggested channel of an Android app, not the transmitter scan, worked well. There's a lot Canon can do though:

1) Improve the channel scan algorithm and auto set channel and ID
2) Fix the transmitter to recognize when link has been lost
3) When link has been lost, re-scan for a clean channel/ID and re-link

[ajlockwood]

Thanks for this.  I've switched the rechargables to alkalines in units that delinked, and that helped one unit but made no difference in another.  I switched to channel 14.  That improved things a little but not a lot.  Also, it seems some units are more sensitive than others.  Although, I have some now going strong for a half hour with no problems.  I'm now going to try WiFiman and setting the ideas to 4 of the same digits as you suggest.  Things are improving, just not fully there yet.  Appreciate all the helpful advice that has been provided.

[Mannies17]

Same exact scenario for my home. If I take it away to a park they’re totally fine. 5 out of the 20 weddings I had this year produced reception interference inside the church or reception hall. For sure is something per location. The wireless routers???

[Mannies17]

Trying this this week for testing. I am so furious with the drops in 2022. My house is for sure one of the culprit locations I’ve run into. 

[Mannies17]

Shame on you Canon for not addressing this. I have called into CPS on the issue and it’s treated like “wow we’ve never heard of this issue before”. Really disappointing for someone who just invested in 3 new EL1’s for 2022. Now I’m STUCK. 

[ajlockwood]

After further testing, it's definitely NOT the batteries.  The suggestion of using the I.D. numbers to 0000, or 1111 or 2222 etc. and using a less frequently selected channel was the best solution.  After doing that, I only had one delink over the course of an hour using four 430EX RT flashes being triggered by the wireless master transmitter version 2.  The next test will be to try it with 10 slaves and see how that goes.  

[Mannies17]

What variable are you guys looking at when using something like Wifiman? I downloaded it and don’t understand what function to use to find a free channel. 

[halocastle]

On the Wireless tab (bottom, center), you'd be looking at the 2.4 GHz band and some clear space.  I have no idea where Canon gets 15 channels.  There are only 14 total in the 2.4 GHz band and only 11 are technical usable in the North America.  Godox has even more (higher numbered) channels.  Who knows?

I only ever use channel 15.  I also bookend my IDs to either 0000 or 9999 (this is where I think the issue is because there are so many and the tolerance -- distance between IDs -- is probably low).

There is no panacea in the 2.4 GHz band, unfortunately.