set_and_wait_for_other_value

The set_and_wait_for_other_value function (defined in _signal.py) is a utility designed to:

1. Set a signal.

2. Wait for another signal to reach a specified value (match_value).

The behavior of the function depends on the value of the wait_for_set_completion parameter:

• If wait_for_set_completion = True:
  The function returns at 1 (see diagram below), which occurs when the “set operation” is complete.

• If wait_for_set_completion = False:
  The function returns at 2, which occurs when the match_signal reaches the match_value.

In AreaDetector, the wait_for_set_completion parameter should generally be set to False, as the preferred behavior is to return when the match_signal achieves the match_value.

---

Behavior Diagram:

---

Example Usage

# Example code snippet for using set_and_wait_for_other_value in an AreaDetector driver
self._arm_status = set_and_wait_for_other_value(
    self._drv.arm,
    1,
    self._drv.state,
    "ready",
    timeout=DEFAULT_TIMEOUT,
    wait_for_set_completion=False,
)

In this AreaDetector driver, the function ensures that the detector’s arm_status reaches "ready" before capturing data. To achieve this:

• The detector is instructed to transition to the “armed” state by setting the driver’s arm signal to 1.

• The function waits until the driver’s state signal equals "ready".

This approach ensures that data capture is only initiated once the detector is fully prepared.