Is there an absolute limit of how many end nodes that can be handled by a single coordinator?

[MartinPersson]

Hello.

If using an nRF52840 as a coordinator, there seems to be a hard limit of 200 connected devices:

#define ZB_CONFIG_OVERALL_NETWORK_SIZE 200U

At least that's how I interpret it; one coordinator can handle up to 200 end devices.
Is that limit of 200 an absolute maximum, or are there ways to circumvent it without having to add a second nRF52840?
Would using routers increase the number, ie 200 end devices per router and then the routers connect to the coordinator?

/Martin

[AHaug]

Hi,

The theoretical number of devices in a Zigbee network is higher than 200, but yes, 200 is what is set in the ZBOSS stack https://developer.nordicsemi.com/nRF_Connect_SDK/doc/zboss/3.12.1.0/group__configurable__mem.html#ga12a2b6986dcbb40fe53930dbd27623dc (overall network size).

Would using routers increase the number, ie 200 end devices per router and then the routers connect to the coordinator?

Not as I understand it. The coordinator acts as the trust center in the network and it has overview over all the nodes in the network. The limitation will thus be in terms of the memory (both flash and RAM) of the coordinator. 

Kind regards,
Andreas

[MartinPersson]

Asch. Not the answer that I wanted, but thank you for letting me know.
We'll simply have to use two coordinators then, or potentially go shopping for some other solution.

Thanks.

/M

[AHaug]

Another update here: Since my initial comment I've also created a discussion with the Zigbee team to verify if my understanding is correct, so I'll return to you with an update when I hear from them.

Kind regards,
Andreas

[AHaug]

Hi again,

I've verified that unfortunately the maximum is set to 200 in the ZBoss stack that we're using in NCS, so I have nothing new to be added to my initial reply

Kind regards,
Andreas

[MartinPersson]

Thank you.
Not the answer I wanted, but at least now we know.

Regards

/M