Quiet Mode is available in the newest BrainStem modules and BrainStem GP 1.0 modules starting with Build 9.

In normal operation, a BrainStem module can receive commands through its serial port while a TEA program is running.  TEA programs may automatically send messages through the serial port when they begin or terminate.  In applications where a TEA program must communicate with a serial device, these messages may cause unreliable operation.  Incoming bytes may be misinterpreted as part of a command by the BrainStem module and outgoing messages may be misinterpreted by the serial device.  The Quiet Mode of operation can prevent these problems.

Quiet Mode discards all serial input unless the input is requested by a running TEA program.  This mode also turns off all automatic status messages so only a running TEA program will output serial data.  Quiet Mode should be used in stand-alone applications where a BrainStem is running a TEA program that is communicating with a device via the serial port.  Quiet Mode is controlled through two ports, aPortQuietFlag and aPortVMQuiet , as well as system parameter 20.  The cmdVAL_SET and cmdVAL_GET commands may be used to access system parameters.

System parameter 20 can be used to configure a module so that it will be in Quiet Mode at power-up or reset.  Any changes to this system parameter will be applied at the next power-up or reset.  When a single module is powered-up in Quiet Mode, the module will require a hard reset (GP) or hard reset (Moto) to disable Quiet Mode.  If the module is in a network, another module or the host may send commands to disable Quiet Mode.

The aPortVMQuiet port provides immediate control of Quiet Mode during TEA program execution.  This mode is useful during the debugging phase of a project.  It enables the user to change the mode with software rather than reconfiguring the module with commands and resets.  Once a stand-alone application with a serial device has been implemented and debugged, the module can be configured to enter Quiet Mode at power-up.