ASITiger — A Python interface for ASI Tiger Controllers

This is a Python package which provides a thin interface for communicating with ASI TG-1000 "Tiger" Controllers. This package is concerned with making low-level interactions with Tiger Controllers easier by providing Python-native arguments to commands, and by parsing out convoluted responses and errors into nicer Python primitives.

Most methods map directly onto the identically named serial command described in the ASI serial commands documentation. Some methods—such as axes—build upon other commands to provide a more useful interface over somewhat-cryptic serial responses.

Caveats

This package is very new and therefore has very few commands actually implemented. I also don't have access to every single ASI Tiger card to be able to test all commands in the serial API. If you'd like more commands added, please open an issue or PR.

For commands which this package doesn't expose an explicit method for yet, you may be able to get away with using the TigerController#send_command(cmd) method, which will allow you to send any arbitrary commands, and knows how to raise exceptions for each known failure response.

Installation

This package is available on PyPI:

$ pip install asitiger

Note: This package has only been tested on Linux, if you run into issues on other operating systems, please open an issue.

Usage

Commands are represented by methods on an asitiger.TigerController object, which can be created from the serial port / COM device it's connected to:

from asitiger.tigercontroller import TigerController

tiger = TigerController.from_serial_port("/dev/ttyS0")

# When done, close the serial connection
tiger.connection.disconnect()

Examples

Here are a few examples showing some of the things you can do. These examples assume you have TigerController object named tiger, like shown in the Usage section.

Check if any motors are busy

You can check to see if any motors are active, and wait for all motors to become idle:

tiger.status() # <Status.IDLE: 'N'>
tiger.is_busy() # True
tiger.wait_until_idle() # Blocks until every motor is idle
tiger.is_busy() # False

Check and set axis speed

Speeds can be get/set through the speed method:

tiger.speed({"X": "?", "Y": "?"})
# {'X': '29.998830', 'Y': '29.998830'}

tiger.speed({"X": 11})

tiger.speed({"X": "?"})
# {'X': '11.000030'}

Move one or more axes

One or more axes can be moved at once, and moves can be sequenced with waits in between:

tiger.move({"X": 50000, "Y": 0})
tiger.wait_until_idle()
tiger.move_relative({"X": -10000, "Y": -20000})
tiger.wait_until_idle()
tiger.move_relative({"X": -10000, "Y": -20000})

Change LED intensity

You can change the intensity of the default LED (on your XYStage card) or directly address a TGLED card:

# Set the default LED to 75% intensity
tiger.led({"X": 75})

# For a TGLED card (with card address 7)
# Set the 1st and 4th LED channels to 100% intensity, and turn all other channels off
tiger.led({"X": 100, "Y": 0, "Z": 0, "F": 100}, card_address=7)

Lock or unlock a well plate

To change the position of a servo or solenoid well plate lock insert, use the higher-level set_plate_lock method, for lower-level control, you can use the secure method:

from asitiger.secure import SecurePosition

# Unlock a plate (servo or solenoid)
tiger.set_plate_lock(SecurePosition.UNLOCKED, card_address=2)

# Lock a plate (servo or solenoid)
tiger.set_plate_lock(SecurePosition.LOCKED, card_address=2)

# Set the lock to a halfway position (servo only)
tiger.set_plate_lock(0.5)

# Set the auto-lock time to 3 minutes:
tiger.secure({"F": 3})

Inspect available axes

You can inspect which cards/axes are installed, or query for axes on specific cards via the optional card_address keyword arg:

tiger.axes()

# [AxisInfo(label='X', type=<Type.XY_MOTOR: 'x'>, address='1', address_hex='31'),
#  AxisInfo(label='Y', type=<Type.XY_MOTOR: 'x'>, address='1', address_hex='31'),
#  AxisInfo(label='Z', type=<Type.Z_MOTOR: 'z'>, address='2', address_hex='32'),
#  AxisInfo(label='S', type=<Type.SLIDER: 'f'>, address='2', address_hex='32'),
#  AxisInfo(label='O', type=<Type.TURRET: 'o'>, address='3', address_hex='33'),
#  AxisInfo(label='L', type=<Type.MULTI_LED: 'i'>, address='7', address_hex='37')]

Check the detailed status of axes

Here the statuses of axes X and O are checked at the same time:

x_axis_status, turret_status = tiger.rdstat(["X", "O"])

print(x_axis_status)

# AxisStatus(
#   status=<Status.IDLE: 'N'>,
#   enabled=<AxisEnabledStatus.ENABLED: 1>,
#   motor=<MotorStatus.INACTIVE: 0>,
#   joystick=<JoystickStatus.ENABLED: 1>,
#   ramping=<RampingStatus.NOT_RAMPING: 0>,
#   ramping_direction=<RampingDirection.DOWN: 0>,
#   upper_limit=<LimitStatus.OPEN: 0>,
#   lower_limit=<LimitStatus.OPEN: 0>
# )

Send commands manually

If a command you want to send isn't currently supported as a first-class method, or you just want to send commands directly as strings:

tiger.send_command("CDATE")
# 'Apr 30 2019:08:48:59'

This method will still detect and raise an exception when the controller responds with an error code.

Logging

This library logs through the logging standard library, but adds a default null handler. If you'd like to see logs from this library, activate logging for the asitiger logger, which is the parent logger under which all loggers for this library live.

import logging

logging.basicConfig()
logging.getLogger("asitiger").setLevel(logging.DEBUG)

tiger.where(["X", "Y"])
tiger.move_relative({"X": -10000, "Y": 10000})

# Log messages:
# DEBUG:asitiger.serialconnection:Sending data: b'W X Y\r'
# DEBUG:asitiger.serialconnection:Received: b':A -989110.5 -1042395.0 \r\n'
# DEBUG:asitiger.serialconnection:Sending data: b'R X=-10000 Y=10000\r'
# DEBUG:asitiger.serialconnection:Received: b':A \r\n'