Problems about modem USB interface

Frequent questions asked online, offline, in forums are answered here
Post Reply
Posts: 2
Joined: Wed Aug 15, 2018 6:34 am

Problems about modem USB interface

Post by yanglx »

I have some problems when operating beacons via modem USB interface.

(1)Setting address of device
I encountered a problem when modifying beacon ID via modem USB interface. Normally the beacon ID is modified after the request is sent, but sometimes the beacon ID is not changed after the request is sent and the correct receipt is received. I used a serial debugging assistant to test the problem by sending a request frame(modifying the ID of beacon 7 to 1) every 2 seconds. In the worst case, the ID was modified after 10 request(20s), as shown in the following figure.
By the way, other request(such as reading device control settings) also has the similar problem.
I have no idea what is the probable cause of this problem. And do you have any suggestions or solutions?

(2)Reading list of devices in network
When I turn off the power of a beacon, it can still be read in the list of devices. It seems like the list of devices is correct only if the map in the modem is erased(by "Erase map" button in Dashboard).
Is there any way to read the correct list of devices at any time?
Or can I erase map via modem USB interface?

question1.png (2.58 KiB) Viewed 2526 times

Posts: 327
Joined: Sat Feb 06, 2016 4:03 pm

Re: Problems about modem USB interface

Post by smoker77 »


1. Commands for changing device address and for reading device control settings require communication with device via radio. So errors may be caused by bad radio connection. Check RSSI values for the beacons, it should be in range -75...-25 dBm for best communication. Try to execute same operations with dashboard and check fails counter in status line on the bottom of the dashboard window. 'Read all' button reads device control settings and all other settings.

2. Modem does not remove device from 'list of devices in network' immediately when you turn off the device. When modem detects loosing connection to the device, it continues tries to communicate with this device during 60 seconds. Only after 60 seconds of disconnect modem stops attempts to communicate with the beacon. If the map is not frozen, modem removes lost device from the 'list of devices in network'. If all submaps are frozen, the modem never removes devices from the list without manual command. If you turn off the device, modem will stop communication with device after 60 seconds, but the device will remain in the list and modem will periodically try to wake the device. This allows to work with system without loosing the devices when some beacons may be temporarily removed (discharged, or turned off, or moved out of radio coverage).

You can manually remove all devices from list by 'erase map' button in dashboard, or remove selected device by 'Remove from network' context menu of the device button in dashboard. Both commands are sent via modem USB interface.

Post Reply