Thread Topology Port Potentially Being Blocked by Putty?

[bb429]

I am trying to conduct a basic topology featuring two NRF52840 boards using the Thread Topology Monitor and a thread application using CLI. Once built and connected with J-link within Segger Embedded Studio I open the terminals coinciding with the COM ports in Putty. However, when I then try to select one of the COM ports on the Thread Topology Monitor I get message: 'Error - Opening COM5: Access denied'. When I close the Putty window I am able to successfully open the serial port within the Topology Monitor but no device shows up as nothing is running anymore. 

I have attempted to look up guides for the Topology Monitor but haven't found one that could cover this issue or that goes into great detail on the setup. I am using NRFSDK for Thread v.4.2.0 and Topology Monitor v0.13.0.

First is there an extensive guide for the Topology Monitor? Second is there a workaround for this issue as I have seen COM ports being used in Putty alongside the topology monitor so this is clearly possible but perhaps my setup is incorrect. 

The errors occurs when the putty window is open, when the connection is closed the COM port is able to be opened but the screen remained blank and no devices were responding.

 

[Edvin]

Hello,

The Thread Topology Monitor (TTM) is kind of like the nRF Connect for Desktop -> Bluetooth Low Energy application (if you have ever used that). 

The DK that you use with the TTM will be programmed with a custom application that is used by the application, so you can't use a custom application (CLI application in your case) on that same DK.

So if you want to see how your CLI node behaves in the thread network, you need an extra DK to use with TTM. Inside TTM, you set up the network parameters, and the TTM node will join the network as a separate node. 

In the figure below, you can see that the node that I circled is called TTM router. So this is the node programmed with the TTM FW, which has joined the network. You can also see the leader marked with the orange Thread logo, and your CLI node will be any of the other nodes.

Best regards,

Edvin

[bb429]

So if I wanted to make a topology of two different DKs then I would need a third to act as the 'monitor' here? Also I don't believe the figure you mentioned was posted as I don't see it. 

[Edvin]

Sorry for the late reply. I was out of office since Tuesday. 

And yes, I appeared to forget to attach the image:

It is just a copy of the image from:

https://www.nordicsemi.com/Products/Development-tools/nRF-Thread-topology-monitor

bb429 said:

So if I wanted to make a topology of two different DKs then I would need a third to act as the 'monitor' here?

Yes. That is correct. The reason for this being that you would need to program the DK that acts as the TTM device with the TTM FW (basically a radio to serial communication application). 

BR,

Edvin