I know what devices provide/accept the two methods of sync, but I never saw an explanation of the technical differences between the two methods. It seems like some products (450i) can accept either and still work and seemingly sync up with each other.
Is it a difference in how the 1PPS is put onto the power signal? Is Cambium sync more robust or more suited to gigabit speeds that modern Cambium devices use?
The actual technical details of how the sync is achieved is somewhat proprietary, but you have the jist of it.
Canopy Sync only works with Fast Ethernet (100BaseT). In order to allow Gigabit Ethernet (1000BaseT) and keep doing sync, the engineers developed Cambium Sync.
The 1PPS signal that the device interprets is (in the Radio Software) exactly the same, and these two methods of providing that pulse can be used together in the same system seamlessly.
about $45 for the correct packetflux injector!
Honestly there is not difference in how the sync works, but there is a difference in the sync start time location and the ethernet speed used as Matt pointed out.
The sync signal from a cmm3 and a cmm5 are the same but the sync in the radios are different. Some devices like the epmp1000 can use either and you just need to tell it which it has, others you must give it the one it is expecting. And in mixing radio systems with differing sync protocols you need to use the user guides to determine if you need to have frequency use offsets to be able to reuse the same frequency channels. Other than that, you design and plan the same as long as all radios use the same sync protocol.
You can have radios using GPS sync, CMM3, CMM4, CMM5… it doesn’t matter… as long as they’re using a common sync source and the correct settings, they can all be sync’d.
Dont try mixing canopy sync with cambium sync unless you follow the pattern in the user guide. There is a difference in how the radios behave and this is pointed out by Cambium clearly.
I realize I’m very late on this reply, but Cambium does support mixing canopy sync and cambium sync on different radios in the same general location. I did a search through our config and installation guides and couldn’t find any instructions that suggested otherwise. But those documents are huge and it’s possible I missed something. Douglas, if you recall where in the Cambium documentation you read this, please do send me a pointer and I’ll take a look… And I’ll clean it up if necessary, thanks.
I didnt say that different systems could not be sync’d, I said that you shouldnt try tobuse different sync sources as specified in the various user manuals. The same user manuals also specify mixing canopy sync and cambium sync with a specific RF sector pattern.
On top of this, I have run a mixed network with different radios and different sync types and it was a a small nightmare until I finally got allnof the older radios out and just used cambium sync.
It would be helpful to have at least a basic technical idea of how Cambium Sync works. I am having a problem at a site where all the APs will suddenly start reporting Cambium Sync is intermittent. Gigabit Ethernet however is error free.
This site is a “grain leg” (private grain elevator at a farm), and I suspect the problem started happening due to harvest activities - either the motors for the grain conveyer or the adjacent grain dryer. We have similar setups at other grain legs with no sync problems.
We know that Canopy Sync used a momentary interruption of the power over Ethernet, and that had its own set of issues. Notably an inductive kick could cause spikes that would trigger surge suppressors and cause Ethernet errors, especially if the cables were tied to a long run of metal or inside metal conduit.
Apparently the mechanism that Cambium Sync uses is a tightly guarded secret. I’m going to guess it is NOT SyncE. Maybe an audio frequency tone burst or something.
From what I’ve been told, Cambium Sync was introduced to fix some issues that the 1 PPS Canopy sync signal had when being used over gigabit ethernet. So if you’re using gigabit ethernet, then you should be using Cambium Sync. Both Cambium sync and Canopy Sync are compatible from a timing perspective.
We’ve had some issues with some inline ethernet surge/lightning suppressors and Cambium sync. If you’re using these and having issues, try temporarily removing one or trying a different brand/make/model and see if the issues go away.
Thanks Eric. We’re using the McCownTech “Cat6 APC” surge suppressors at this site, they are very minimal (just 4 x dual gas tubes). I have added a bunch of SNMP monitoring of 1pps parameters on both the Packetflux equipment and the APs. The problem is intermittent, which makes it hard to decide if any change has helped or not.