Trigger

Trigger

The Trigger Conditions panel may be accessed in either of two ways:

Click on the Pane / Trigger menu item.
Click on the Trigger button.

Trigger includes menu options for beginning and ending signal data acquisition, such as by manually clicking on the Go and Stop buttons, or through the use of external inputs such as motor movement.

The Trigger Conditions panel is divided into four different sections, each of which is described below, along with their respective menu items.

Pre-Condition

The Pre-Condition defines the Motion Supervisor state that must occur before the Motion Start trigger condition can be triggered.

Wait for Motion Done – Motion Start trigger cannot be activated until the Motion Supervisor transitions from the Idle state to the Moving state.

None – Motion Start trigger can be activated whenever the Motion Supervisor is in the Moving state.

The wait for "at rest" pre-condition is useful when the trigger Repeat is enabled and the motion is continually commanded back and forth between two points. In this situation, the wait for "at rest" will guarantee that the data is acquired at the start of the move, instead of sometime during the middle of the motion.

Start Condition

The Start Condition defines the triggering event to start data acquisition. Possible sources for triggers include the Go button, a Motion Start, or a User definable condition.

Go button – Traces are started when the Go button is clicked on the front of the display pane. Selecting this option displays two support buttons on the front of the display pane:

Go – Tracing begins immediately after the Go button is clicked.
Stop – Tracing is halted when the Stop button is clicked.

Motion Start -- Tracing begins when movement is detected in the Motion Supervisor chosen for tracing after the Arm button is clicked on the display pane. Selecting this option displays two support buttons on the front of the display pane:

Arm – The Arm button is displayed on the display pane whenever Motion Start is selected. Tracing does not begin until the Arm button has been clicked; tracing ends according to the condition set in the "End Condition" box of the Trigger Conditions panel (see below).
Repeat – The Repeat button is used to continue data acquisition beyond a single pane, after the Arm button has been clicked. The previous move data will be overwritten and the new move data will be displayed.

External Event – (Not yet implemented.)

Pre-Acquire (ms) – [Usable only when Motion Start enabled.] Amount of data to include with plot before triggered data.1

User Condition – Data acquisition begins when the user-defined trigger conditions are met. To configure the conditions, click the Define button.

The trigger properties menu allows you to configure the trigger conditions.

Address – Controller memory address in hex. To determine the memory address use the VM3 utility program.

Mask – Data located at the Address is masked (bitwise ANDed with the Mask value).

Pattern – Masked data is compared to the expected Pattern value. The Condition determines how the data is compared to the Pattern.

Count – The number of data samples to be acquired after the trigger is activated. The Mode determines whether the Count is applied.

Condition:

Change – When the masked data at the address is not equal to the Pattern, the trigger is activated.
Match – When the masked data at the address is equal to the Pattern, the trigger is activated.

Mode:

Continuous – Count value is ignored and data is continuously acquired until the End Condition is met.
Count – Count value is applied.

Example

If you want to start your recording when bit 3 (2³ = 0x4) of the word at 0xa01000 is low, you would set the following conditions:

edit trigger properties

End Condition

The End Condition defines how tracing is to be halted.

Stop button – Tracing ends when the Stop button is clicked on the main display panel.

Buffer Full – Tracing ends when the data buffer has filled. NOTE: the data buffer size is set by the MaxBuffer field on the main display pane and may be as large as 50000 ms.

Motion Done – Tracing ends when motion halts (i.e., when MotionDone condition is TRUE).

External Event – (Not yet implemented in Version 1.19.07.)

User Condition – Data acquisition begins when the user defined trigger conditions are met. To configure the conditions click the Define button.

The trigger properties menu allows you to configure the trigger conditions.

Address – Controller memory address in hex. To determine the memory address use the VM3 utility program.

Mask – Data located at the Address is masked (bitwise ANDed with the Mask value).

Pattern – Masked data is compared to the expected Pattern value. The Condition determines how the data is compared to the Pattern.

Count – The number of data samples to be acquired after the trigger is activated.

Condition:

Change – When the masked data at the address is not equal to the Pattern, the trigger is activated.
Match – When the masked data at the address is equal to the Pattern, the trigger is activated.

Motion Start/Done Trigger Source

If either the Start Condition or End Condition fields are set to Motion Start or Motion End respectively, the Trigger Source field will be enabled. This field specifies which Motion Supervisor is used to trigger start and/or end of tracing.

1. Acquisition of data is ongoing, even before the start of tracing. When a Pre-trigger time is entered, the display will include buffered data of Pre-trigger length with the triggered trace.

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