DCU (Deployable Calibration Unit) Documentation

The Observatories of the Carnegie Institution for Science (Carnegie Observatories), Pasadena, CA

Version 1.4

Christoph C. Birk (birk AT carnegiescience DOT edu)

Location of this document: http://instrumentation.obs.carnegiescience.edu/Software/DCU/dcu.html

  • News
  • Screen Shots
  • Troubleshooting

    Further documentation:

  • The official DCU User Manual (TODO: not yet available)
  • AppleScript Guide
  • PLC Memory Address List

    News

    2024-12-13: The code has been moved to GitHub

    v1.4 (2022-10-30)
  • Added a TCP/IP server that listens for status requests of the FF-Screen and the lamps.
    • Command: ffsState
    Response: { retracted, deployed, unknown }
    Command: ffsLamps
    Response: "Off" or a string with the labels of the lamps that are on, eg. "Ar He".
    IFUM is currently the only instrument sending these requests.
  • HighSierra deployment target.
    • v1.3 (2017-09-05)
  • Send a notification when Mcal or the FFS deploys or retracts.
    • M2FS is currently the only instrument that listens to the Mcal notifications.
    Release Notes

    Screen Shots

    TCP/IP Interface

    Command: ffsState
    Response: { retracted, deployed, unknown }

    Command: ffsLamps
    Response: "Off" or a string with the labels of the lamps that are on, eg. "Ar He".

    Troubleshooting

    Problem: "DCU GUI not responding twice complaining about not recieving a cookie. Once just after the network problem started, another after it got fixed, but probably unrelated. A restart fixed the issue on both cases.
    Explanation: The DCU-GUI sends at startup a "magic" (random) number (ie. cookie) to the PLC. The GUI then occasionally checks this cookie to verify that:
    • no other DCU-GUI has been started on a different computer
    • the PLC has not been power-cycled during the current session
    Any of these conditions could lead to an inconsistent state between the GUI, the PLC and the DCU.
    Recommendation: Close the GUI, fix the network, and restart the GUI.

    2013-06-24, Christoph C. Birk, Carnegie Observatories