CALL:DCONnected

Last updated: July 25, 2008

CALL:DCONnected[:STATe]?

Function

This command queries whether or not the data connection is in the connected state (see Connected State for a description of this data connection state).

When the query is sent:

If the data connection is in the connected state, the query immediately returns a 1.
If the data connection is in any other non-transitory state, the query immediately returns a 0.
- See TAP/ETAP/MCTAP Data Connection Processing Lifecycle for information about which states are transitory and non-transitory when the test set is configured to use the Test Application protocols (see Test Application Protocol ).
- ( Lab Application Only) See Packet Data Connection Processing States Lifecycle for information about which states are transitory and non-transitory when the test set is configured to use the Default Packet Application (see Session Application Type ).
If the data connection is in a transitory state, the query waits until the data connection reaches a non-transitory state, and then returns a 1 if the state is connected or a 0 if the state is any other non-transitory state.

NOTE

The query will hang as long as the data connection is in a transitory state. However, the AT includes protocol timers which limit the time it may stay in a transitory state. So, the AT should force the connection to return to a non-transitory state after its protocol timers expire, and so the query will not hang forever.

The query behaves differently if the data connection state change detector (see Data Connection State Change Detector ) is armed when the query is sent:

If the data connection is in a non-transitory state, the query hangs until the data connection state reaches a different non-transitory state, then returns a 1 if the state is connected or a 0 if the state is any other non-transitory state. For example, if the data connection is in the connected state when the query is sent, the query hangs until the data connection leaves the connected state, reaches another non-transitory state such as idle or session open, and then returns a 0.
If the data connection is in a transitory state, the query hangs until the data connection reaches a non-transitory state, and then returns a 1 if the state is connected or a 0 if the state is any other non-transitory state.

NOTE

If the data connection state change detector timeout (see Data Connection State Change Detector ) expires before the data connection moves to a different non-transitory state, then the change detector is disarmed, which releases the query. The query will then immediately return a 1 for connected, 0 for idle or session open, or hang until any non-transitory state is reached or the AT protocol timers expire.

Using the CALL:DCONnected? query in conjunction with the data connection state change detector is useful in determining whether an attempt to open a connection has been successful. See Open a Connection from the Test Set and Data Connection State Synchronization .

Requirements

Test Application Revision: A.01.20 and above
Lab Application Revision: A.01 and above

Query

Range: 1|0

*RST Setting

Programming Example

 
OUTPUT 714;"CALL:DCONnected:STATe?" 
! Queries whether the data connection state is connected.

CALL:DCONnected:ARM[:IMMediate]

Function

Arms the data connection state change detector. See Data Connection State Change Detector .

This is an overlapped command, and therefore has a Pending Operation Flag (POF) associated with it. The POF is set when the change detector is armed, and cleared when the change detector is disarmed. See Data Connection Processing Event Synchronization for more information about the behavior of overlapped commands.

Requirements

Test Application Revision: A.01.20 and above
Lab Application Revision: A.01 and above

Programming Example

 
OUTPUT 714;"CALL:DCONnected:ARM"
! Arms the data connection state change detector.

CALL:DCONnected:ARM:STATe?

Function	Queries the arm state of the data connection state change detector. This command never hangs and immediately returns a one if the detector is armed, or a zero if the detector is not armed. See Data Connection State Change Detector .
Requirements	Test Application Revision: A.01.20 and above Lab Application Revision: A.01 and above
Query	Range: 1\|0
*RST Setting	0
Programming Example OUTPUT 714;"CALL:DCONnected:ARM:STATe?" ! Returns the arm state of the data connection state change detector.

CALL:DCONnected:TIMeout

Function	Sets/queries the maximum time the test set will wait for the data connection state change detector to become disarmed (see Data Connection State Change Detector ). Default setting units are seconds. To set timeout time in units other than seconds, include an optional unit specifier in the command string.
Requirements	Test Application Revision: A.01.20 and above Lab Application Revision: A.01 and above
Setting	Range: 0 to 100 seconds Resolution: 0.1 seconds
Query	Same as setting
*RST Setting	10 seconds
Programming Example OUTPUT 714;"CALL:DCONnected:TIMeout 3" ! Sets the CALL:DCONnected:STATe? query timeout time to 3 seconds. OUTPUT 714;"CALL:DCONnected:TIMeout 500 MS" ! Sets the Sets the CALL:DCONnected:STATe? query timeout time to 500 milliseconds.