Symbol MC70 User Manual

Maintenance & Troubleshooting

6 - 5

Piconet (the 
connection between a 
Bluetooth master and 
one or more 
Bluetooth slaves) 
drops.

The EDA suspends and 
the Bluetooth radio power 
turns off.

One of the devices are out 
of range.

An application can register for notification of an EDA resume by 
creating a message queue using the CreateMsgQueue() API 
and power notifications using the RequestPowerNotifications() 
API (refer to the SMDK Help File). After an application receives 
a resume notification it should close open Bluetooth sessions 
and reopen them.This reestablishes the piconet lost during the 
suspend.

My application 
created a successful 
RFCOMM session 
with another 
Bluetooth device but 
the session was 
dropped.

Device went out of range or 
was shut off.

Check the return value of APIs for errors. Look for a DCD state 
change event in the Microsoft Bluetooth stack DCD window of 
the Bluetooth connection.

After completing an 
RFCOMM session 
with another 
Bluetooth device, I 
was unable to create 
a virtual COM port to 
connect to another 
Bluetooth device.

The Microsoft Bluetooth 
stack holds a baseband 
connection for ten seconds 
after an application closes 
its session and exits. This 
was designed to allow for 
speedy connections to the 
same device if other 
profiles were to connect. 

Either wait 10 seconds, choose a different COM port number for 
the virtual COM port, or modify 
HKLM\software\Microsoft\bluetooth\l2cap\IdlePhys (which 
defines the number of seconds to hold the connection).