ATMCS User Guide

Due to the primary use-case (tracking a star) of the ATMCS requiring 20 Hz command rates, positioning is not performed at the CSC level. Users are encouraged to read the documentation of that ATCS class for most standard operations when being commanded by the LSST control system.

A detailed user guide on using and interacting with the settings of the the ATMCS, specifically via the engineering user interface (EUI) is found in Docushare. This guide discusses many aspects of manual operation, including procedures for over-rides, log file descriptions, and parameters which may require adjustments of the deployed INI file.

The AuxTel utilizes power-off braking, meaning that the brakes to the motors are always engaged except with the ATMCS is in the ENABLED state.

ATMCS Engineering User Interface (EUI)

The engineering user interface is hosted on the cRIO and accessible using a LabVIEW plugin for internet explorer 6. Once connected to the summit control network, the GUI is reached using this address. More details on connecting to and using the EUI are found in the manual on Docushare.

Usage of a hand paddle is also supported. The hand-paddle plugs into a box located on the lower right-hand side of the TCS cabinet. Once active, standard motions are available via the touch screen. Most speeds/parameters are adjustable. Note that external commands to the ATMCS are blocked when the hand-paddle is activated.

ATMCS Interface

The interface to the ATMCS is most often used by the ATCS class, and more specifically the AT pointing component. The startTracking and stopTracking commands dictate when tracking should commence and stop. When tracking a target, a PVT vector (Position, Velocity, Time) is sent to the mount at 20 Hz using the trackTarget command. This command carries the information required for all axes in order to follow the star/target. The mount then calculates and executes the trajectory necessary to have track the vector.

The only other command of interest to the user is setInstrumentPort which dictates how M3 should be rotated in order to direct the light into the instrument of interest. Note that once in position, the motor is powered off to not generate heat. The nasmyth port motor which is not receiving light is also powered off. It is possible to leave this motor enabled but this requires modification of the INI file (as explained in the User Manual).

Example Use-Cases

Interacting with the ATMCS should utilize the ATCS class, where examples are provided to slew the telescope.


The ATMCS has a simulator for the purposes of testing other code on the NCSA Test Bed. It is written in Python and only simulates the functionality of the ATMCS, it does not utilize any of the original ATMCS code. The simulator is found in the ts_ATMCSSimulator repository on Github.