Xeryon Motion Controller Library

Python interface to Xeryon precision piezo stages, over USB serial or over a serial-to-Ethernet terminal server.

Xeryon.py is the manufacturer's library, vendored with a handful of documented changes; see VENDOR_PATCHES.md. XeryonController wraps it in the hardware_device_base interface the other COO drivers implement, and is what applications should use.

Getting started

Prerequisites

• Python 3.8+
• pyserial, hardware_device_base
• A Xeryon XD-C, XD-M or XD-OEM controller

Usage

from xeryon import Stage, XeryonController

controller = XeryonController(settings_file="config/settings_FEI_XD24494_20250828.txt")
# Declare every axis the controller has, wired or not: the library matches
# replies to axes by their position in this list
controller.add_axis("A", Stage.XLS_5_3N, units="mm")
controller.add_axis("B", Stage.XLS_5_3N, units="mm")
controller.add_axis("C", Stage.XLS_5_3N, units="mm")

controller.connect(host="192.168.29.100", port=10001)   # or com_port="/dev/ttyACM0"

controller.close_loop("A")
controller.home("A")                 # searches the encoder index
controller.set_pos(1.5, "A")         # returns as soon as the move is commanded
while controller.is_moving("A"):
    pass
print(controller.get_pos("A"))

controller.disconnect()

Motion calls return once the command is queued. Pass blocking=True to home() or set_pos() to wait for completion instead, and flush_commands() to wait for a queued command to reach the controller without waiting for the motion it starts.

Connecting without disturbing the stage

connect() defaults to leaving the controller as it found it:

• do_reset=False skips the axis reset. A reset invalidates the encoder index, so resetting on every connect would cost a referenced stage its reference.
• send_settings=False loads the settings file into the library (which needs it for unit conversion and travel limits) without pushing it to a controller that already has those settings in flash.

Pass either as True to get the manufacturer's behavior back.

Settings files

Each controller needs its own settings file, as generated by the Xeryon Windows interface; see config/. Lines are TAG=value, prefixed with the axis letter on multi-axis controllers, and % starts a comment:

A:LLIM=-25
A:HLIM=25
A:SSPD=5
POLI=97

get_limits() reports LLIM/HLIM from this file, since the controller only echoes them back when echo is enabled.

Logging

The library logs through the standard logging module, under the xeryon.Xeryon logger; XeryonController logs under hardware_device_base's configuration. Nothing is printed.

Tests

python -m pytest

The tests run against a fake controller port, so no hardware is needed.