Inspect or rehearse a plan (“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.

# Make a RunEngine instance.
from bluesky import RunEngine
RE = RunEngine({})

from ophyd.sim import motor, motor1, motor2, det
from bluesky.simulators import print_summary, plot_raster_path
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.

print_summary(count([det]))
print_summary(scan([det], motor, 1, 3, 3))
print_summary(outer_product_scan([det], motor1, 1, 3, 3, motor2, 1, 2, 2, False))

Out:

=================================== Open Run ===================================
  Read ['det']
================================== Close Run ===================================
=================================== Open Run ===================================
motor -> 1.0
  Read ['det', 'motor']
motor -> 2.0
  Read ['det', 'motor']
motor -> 3.0
  Read ['det', 'motor']
================================== Close Run ===================================
=================================== 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 ===================================

Use plot_raster_path to visualize a two-dimensional trajectory.

plot_raster_path(outer_product_scan([det], motor1, 1, 3, 3, motor2, 1, 2, 2, False),
                 'motor1', 'motor2')

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({})