CALL:IDLE:DATA?

CALL:IDLE:DATA?

Last updated: July 25, 2008

GPIB Command Conventions

CALL:IDLE[:STATe]:DATA?

Function

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

When the query is sent:

  • If the data connection is in the idle 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 non-transitory).
  • 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 idle 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 idle or a 0 if the state is any other non-transitory state. For example, if the data connection is in the idle state when the query is sent, the query hangs until the data connection leaves the idle state, reaches another non-transitory state such as session open or connected, 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 idle 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 idle, 0 for session open or connected, or hang until any non-transitory state is reached or the AT protocol timers expire.
   

Using the CALL:IDLE:DATA? query in conjunction with the data connection state change detector is useful in determining whether an attempt to close a session has been successful. See Close the Session 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

 1

Programming Example

 
OUTPUT 714;"CALL:IDLE:DATA?"
!Queries whether the Data Connection state is idle.