Timing-Event Based Generation of HW-Triggers

Often HW-triggers or gate signals have to be generated which are triggered by Timing-Events. SCU front-ends provide to generate such HW signals with HW precision. Software is only needed to configure the Triggers, but is not involved to generate the outputs.

Generating timing-system related HW-outputs is a two-stage process.

Tag Generation

The timing receiver (ECA-unit) provides to generate tags on the SCU-bus upon reception of timing-events. A tag is a 32-bit identifier which can be assigned to a timing-event. Assignment of tags to timing-events can be configured by the timing library software. The tag number can be freely chosen, no specific values are predefined.

As with all timing-triggered actions, filtering of timing-events is provided. Filtering comprises especially the Group-Id, to select timing-areas.

When a tag is assigned to a timing event, the tag is dstributed on the SCU bus.

Tag Evaluation

Each SCU-bus slave card has access to the tags on the SCU-bus. If applicable, SCU-bus slave cards provide for reaction to tags on the SCU-bus.

E.g. digital I/O-cards provide for generation of triggers and gates:

• a set of 32-bit Tag-Mask registers is provided, to select specific tags
• for each Tag-Mask register selection is provided for
  • level of the output (-1, - 0)
  • bit in the output-word (pin on the output-connector)

In addition, delay counters will be provided to support pulse generation and delayed outputs.

The mentioned registers provide for flexible generation of a wide range of signals with HW precision.

Overview

• TimingHW -Trigger.jpg: