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Information and setting functions

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cliquot22 edited this page Jun 9, 2026 · 20 revisions

These functions read board information, configure motor speeds and limit behavior, read and write motor configuration stored on the board, and manage the serial port connection.

Board Firmware Revision

MCR.MCRBoard.readFWRevision() -> str

controllerClass function. Read the firmware version string from the board.

Returns Firmware version as a string (e.g. '5.3.1.0.0'), or None if no response.

Example

fw = MCR.MCRBoard.readFWRevision()
print(f'Firmware version: {fw}')

Board Serial Number

MCR.MCRBoard.readBoardSN() -> str

controllerClass function. Read the serial number of the MCR600 board.

Returns Serial number as a string (e.g. '055-001234'), or an empty string if no response.

Example

sn = MCR.MCRBoard.readBoardSN()
print(f'Board SN: {sn}')

Set Motor Speed

motor.setMotorSpeed(speed) -> int

motor class function. Set the speed used for all subsequent moves on this motor. The speed is stored in the module only — it is not written to the board EEPROM. It should be within the speed range stored on the board (see readMotorSetup()).

Speed ranges:

  • Focus / zoom: 100 – 1500 pps
  • Iris: 10 – 200 pps

Parameters

Name Type Description
speed int New speed in pulses per second (pps)

Returns

Value Meaning
0 Success
-69 (ERR_RANGE) Speed is outside the acceptable range

Example

MCR.focus.setMotorSpeed(800)
MCR.zoom.setMotorSpeed(1200)
MCR.iris.setMotorSpeed(50)

Set Homing Speed

motor.setHomingSpeed(speed) -> int

motor class function. Set the speed used when homing the motor (seeking the PI limit switch). This applies to focus and zoom motors only. Like setMotorSpeed(), this is stored in the module and not written to the board EEPROM, but it should be within the board's configured speed range.

Speed ranges:

  • Focus / zoom: 100 – 1500 pps

Parameters

Name Type Description
speed int Homing speed in pulses per second (pps)

Returns

Value Meaning
0 Success
-69 (ERR_RANGE) Speed is outside the acceptable range

Example

MCR.focus.setHomingSpeed(600)

Set Respect Limits

motor.setRespectLimits(state) -> bool | None

motor class function. Control whether the motor stops at the PI limit switch position or is allowed to move past it.

When True (the default), moveAbs() and moveRel() will not allow the motor to cross the PI position. Set to False when a target step requires moving past the PI, such as accessing the full range on the far side of the limit switch. When moving past the PI position, backlash it not automatically handled due to the possibility of the motor hitting the hard stop and losing it's position information.

Only applicable to focus and zoom motors. Returns None for iris and IRC.

Parameters

Name Type Description
state bool True to enforce the PI limit; False to allow movement past it

Returns The new respectLimits state (True/False), or None if the motor has no PI.

Example

# Allow focus to move past the PI limit
MCR.focus.setRespectLimits(False)
MCR.focus.moveRel(100)
MCR.focus.setRespectLimits(True)

Read Motor Configuration

motor.readMotorSetup() -> tuple

motor class function. Read the motor configuration stored in the MCR IQ 600 board EEPROM. This includes the motor type, limit switch enable flags, step range, and speed range.

Returns An 8-element tuple:

Index Name Type Description
0 success bool True if the board returned a valid response
1 motorType int 0 = stepper motor, 1 = DC motor; or error code if success is False
2 useWideFarStop bool Left (wide/far) limit stop enabled
3 useTeleNearStop bool Right (tele/near) limit stop enabled
4 maxSteps int Maximum number of steps
5 minSpeed int Minimum speed (pps)
6 maxSpeed int Maximum speed (pps)
7 errorVal int 0 (ERR_OK) or error code

All values may be -1 or False if success is False.

Example

success, motorType, wideFarStop, teleNearStop, maxSteps, minSpeed, maxSpeed, errVal = MCR.zoom.readMotorSetup()
if success:
    print(f'Zoom: max steps={maxSteps}, speed range={minSpeed}-{maxSpeed} pps')

Write Motor Configuration

motor.writeMotorSetup(useWideFarStop, useTeleNearStop, maxSteps, minSpeed, maxSpeed) -> bool

motor class function. Write the motor configuration to the MCR IQ 600 board EEPROM. The configuration persists after a board power cycle.

Parameters

Name Type Description
useWideFarStop bool Enable the left (wide/far) limit stop
useTeleNearStop bool Enable the right (tele/near) limit stop
maxSteps int Maximum number of steps
minSpeed int Minimum speed (pps)
maxSpeed int Maximum speed (pps)

Returns True if the board confirmed the write, False otherwise.

Example

success = MCR.zoom.writeMotorSetup(
    useWideFarStop=True,
    useTeleNearStop=False,
    maxSteps=3227,
    minSpeed=100,
    maxSpeed=1500
)

Check and Restart Board Communication

MCR.checkBoardCommunication() -> bool

Top-level function. Verify that the serial port is open and the MCR board is responding. If the initial check fails, the serial port is closed and reopened, and the board is tested again. Returns the result of the final communication test.

Use this function to detect and recover from temporary USB disconnections in long-running applications.

Returns True if communication with the board is working, False if it cannot be restored.

Example

if not MCR.checkBoardCommunication():
    print('Board communication lost — check USB connection')
else:
    print(f'Communication OK (restarts so far: {MCR.boardCommunicationRestarts})')

Board Communication Path

MCR.MCRBoard.setCommunicationPath(path) -> bool

controllerClass function. Change the communication interface used by the board. The first connection when receiving the board (or factory resetting the board) will be made over USB. Once connected, this function can switch the board to I2C or UART for subsequent sessions. After setting a new path, the board reboots — wait at least 700 ms before sending further commands. The original USB connection will no longer be active after this command.

This TheiaMCR module will no longer be available without user modification to the sendCmd() function. This function must be modified to support the new I2C or UART protocol by the user.

See Theia motor driver instructions for wiring details for UART and I2C connections.

Parameters

Name Type Description
path int or str New communication path: 'I2C' or 0, 'USB' or 1, 'UART' or 2

Returns True if the command was sent successfully. The board reboots and the current connection is lost regardless of return value.

Example

import TheiaMCR as mcr
import time

MCR = mcr.MCRControl('com4')

# Switch to UART communication
MCR.MCRBoard.setCommunicationPath('UART')

# Wait for board reboot (>700 ms)
time.sleep(1)
# Reconnect on the new path

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