DSM_ADDR_MAX_LIMIT - is it possible to increase this?

[timvan]

Hi,

I am creating an application in which there are ~12 elements per device and could have >20-30 devices. I would like to individually address each of these using a serial device. I quickly found that i've reached the maximum number of address that the serial device can store, after updating the max values in nrf_mesh_config_app.h.

I found the hard limit:

DSM_ADDR_MAX_LIMIT (185) in device_state_manager.h

Is it possible to increase this limit? How can I store a large number of addresses on a devices so that I do not have to do the inefficient multi step method of adding and removing addresses? 

Many thanks in advance,
Tim

- mac OSx
- nRF5 SDK for Mesh v3.1
- PCA10040 nRF52 Dev boards with Serial Example and Custom Server/Client application

[Joakim Jakobsen]

Hi Tim. 

Is it possible to increase this limit?

I've talked to our Mesh developers, and there is no quick fix to increase that limit. 

Your question has been forwarded internally, so that our Mesh team can take a closer look. 
I'll get back to you with an update. 

Best regards, 
Joakim

[Joakim Jakobsen]

A couple of follow-up questions from the Mesh team: 

1. Is the serial interface going to be implemented in each device or is there only one single device.
2. Do you want to qualify the serial device as a Bluetooth product? Because changing this value might create assertions in the stack.

[timvan]

Hi Joakim, sorry for the delay in response. In replay to your questions:

1. We are trying to use mesh as the communication bearer for our farm control systems. The serial device will act as interface between the mesh network and central control system. So the serial interface will only be deployed on one device. The other device will have a custom control firmware, with a variety of vendor made models and it's likely that they'll be a single element per device.

2. At this stage I am not sure about qualification, however it useful to keep the options open.

[Joakim Jakobsen]

No problem. 

I'll forward the information to our Mesh team. 

Cheers, 
Joakim

[Joakim Jakobsen]

Information from our Mesh team: 

If a qualification is not going to be done, then it is possible to change this value. This limit was added to ensure that the response to the Subscription List Get message goes not exceed the maximum possible PDU size for the access message. If this value is changed and those many addresses are simultaneously active in the model subscription list, a user should not send Config SIG/Vendor Model Subscription Get messages, if this happens, a node will not send any response for this messages.

Best regards, 
Joakim