IviDmm Behavior Model
The following state diagram shows relationships between the IviDmm base capability group and DMM behavior.
IviDmm Behavior Model
The main state in the IviDmm Class is the Idle state. The DMM enters the Idle state when it is powered-on, when it successfully completes a measurement, or when you call IviDmm Abort from a previous measurement. Typically, you configure the DMM while it is in the Idle state. IviDmm properties can be configured individually with the property node or with the high-level IviDmm Configure Measurement VI.
The IviDmm Read and IviDmm Initiate VIs cause the DMM to leave the Idle state and transition to the Wait-For-Trigger state. The IviDmm Read VI does not return until the measurement process is complete and the DMM has returned to the Idle state. The IviDmm Initiate VI returns as soon as the DMM leaves the Idle state.
The DMM leaves the Wait-For-Trigger state when it receives a trigger event. The type of trigger event is specified by the property IviDmm Trigger Source.
After the specified trigger event occurs, the DMM waits the amount of time specified by the property IviDmm Trigger Delay and then takes a measurement. The type of measurement is specified by the IviDmm Function, IviDmm Range, and IviDmm Resolution properties.
If you set the IviDmm Function property to a value that requires an extension capability group, the properties of that capability group further configure the measurement.
After the measurement is taken, the DMM (if it is capable of doing so) generates the Measurement Complete signal and returns to the Idle state.
The IviDmm base capability group does not require that a DMM be able to generate a Measurement Complete signal. The Measurement Complete signal is presented in the Base Capabilities State Diagram to define when the signal is generated as most DMMs generate this signal but may not be able to configure it.
The IviDmm Fetch VI is used to retrieve measurements that were initiated by the IviDmm Initiate VI. The measurement data returned from the IviDmm Read and IviDmm Fetch VIs is acquired after the DMM has left the Wait-For-Trigger state.