How to get notification for device disconnection

[biswadeepdey-eaton]

I am using device-modbus service to talk to a meter using Modbus TCP. I have subscribed to "edgex/events/#" to get all the events related to the device. However when I disconnect the device I am not getting any notification. Am I missing any configuration?

I can see in the logs for device-modbus when it says gateway path is no available. this is helpful for debugging but how can i get the disconnect notification

[cloudxxx8]

@biswadeepdey-eaton we added this mechanism in v4.0 for both Device Go and C SDK
edgexfoundry/device-sdk-go#1665

Once the device is disconnected, device service will change the operatingState to DOWN in core-metadata.
You can subscribe the System Event of core-metadata to see which device operating becomes DOWN or UP
https://docs.edgexfoundry.org/4.0/microservices/core/metadata/details/DeviceSystemEvents/

For example, subscribe edgex/system-events/core-metadata/device/update/#