Inspect or rehearse a plan without touching hardware (“simulation mode”)

Problem

Check a plan for mistakes before running it on real hardware.

Approach

1. Display the steps of a plan and read through them to verify that they match our intention.
2. Execute the plan on “simulated hardware,” Python objects that stand in for real motors and detectors but do not actually communicate with any hardware.

Example Solutions

The bluesky.examples module includes simulated motors and detectors.

# Import simulated motors and a detector.
from bluesky.examples import motor, motor1, motor2, det

# This may already be imported in the configuration.
from bluesky.plan_tools import print_summary
from bluesky.plans import count, scan, outer_product_scan

Inspect plans

Use print_summary which translates the plan into a human-readable list of steps.

In [1]: print_summary(count([det]))
=================================== Open Run ===================================
  Read ['det']
================================== Close Run ===================================

In [2]: print_summary(scan([det], motor, 1, 3, 3))
=================================== Open Run ===================================
motor -> 1.0
  Read ['det', 'motor']
motor -> 2.0
  Read ['det', 'motor']
motor -> 3.0
  Read ['det', 'motor']
================================== Close Run ===================================

In [3]: print_summary(outer_product_scan([det], motor1, 1, 3, 3, motor2, 1, 2, 2, False))
=================================== Open Run ===================================
motor1 -> 1.0
motor2 -> 1.0
  Read ['det', 'motor1', 'motor2']
motor2 -> 2.0
  Read ['det', 'motor1', 'motor2']
motor1 -> 2.0
motor2 -> 1.0
  Read ['det', 'motor1', 'motor2']
motor2 -> 2.0
  Read ['det', 'motor1', 'motor2']
motor1 -> 3.0
motor2 -> 1.0
  Read ['det', 'motor1', 'motor2']
motor2 -> 2.0
  Read ['det', 'motor1', 'motor2']
================================== Close Run ===================================

Note that print_summary cannot be used on plans the require feedback from the hardware, such as adaptively-spaced step scans.

Rehearse plans

Simply execute the plan as usual — RE(plan) — but define that plan using the simulated motors and detectors from bluesky.examples instead of the variables that represent real hardware.

RE(count([det]))  # executes the plan, 'reading' the simulated detector

To avoid saving data from these “rehearsal” runs, make a separate instance of the RunEngine, and do not subscribe metadatastore.

SIM_RE = RunEngine({})