MODS Software Description

This page was created from an outline Rick Pogge created about software while preparing for the MODS2 PAO.
The first version is mostly directly from Rick's notes, with Kellee filling in some ofthe references.

Overview and Scope

Hardware and Software Functional Block Diagram

Need diagram including communication protocols between subsystems

MODS computer architecture diagram from MODS Network Infrastructure Requirements v1.0 (Oct-2013) - excellent hardware info:

MODS Software System Overview


Overview of the MODS software system, shown for a single MODS instance (#=1 or 2). Both MODS have identical underlying systems that operate independently. The dashed boxes enclose programs running on particular host computers, with the exception of "LBTO Systems" which is a blanket container for all LBTO subsystems that the MODS data-taking systems interact with.

Interface protocols are shown in the key at the lower left corner. "Ethernet" is a mix of TCP/IP and UDP/IP depending on the system. Optical fibers are either Fiber Ethernet (the one into the IUB) or dedicated dedicated data I/O fibers for the MODS science CCDs and the AGw Guide and WFS cameras. "Virtual C&C" is a catch-all indicating "other" virtual command-and-control protocols, for example the modsTCS to LBT IIF processes communicate via the Zero-C ICE interface, whereas the LBT GCS and MODS AGw server and Az Cam servers communicate using a TCP/IP socket interfaces.

We show the MODS GUI program running on an obsN workstation, but note that this is just a window into the "modsUI" program running on the mods1/mods2 linux host, with the GUI portion instantiated on the obsN workstation via X tunneling through an ssh session between the observer account on obsN and the relevant mods# host computer.

In binocular MODS mode, the acqMODS and execMODS programs are run via a wrapper script that makes sure that the appropriate binocular context flag is set, and which permits both sides to be running either the same acquisition or observation script ("identical twin mode") or different acq/obs scripts for each MODS ("fraternal twin mode").

Instrument Electronics Box (IEB)

The functional block diagram of the Instrument Electronics Boxes (IEBs) as they relate to the IE server program above is shown below. It shows the mapping between mechanism motor controllers and specific mechanisms inside a MODS, WAGO units that control power management and environmental sensor readout associated with each box, and the instrument ethernet connection points and distribution internal to each IEB. Each MODS has two IEBs, red and blue.


To be written:

More description of the figure above...

Instrument Utility Box (IUB)

Instrument Utility Box (IUB) functional description and block diagram


Description of the IUB and its function

Lamp/Laser Box (LLB)

Lamp/Laser Box (LLB) functional description and block diagram

CCD Head Electronics Box (HEB)

CCD Head Electronics Box (HEB) functional description and block diagram

Data-Handling & Archiving System ("Caliban")

Data-Handing System (aka "Caliban") functional description and you get the general idea...

Instrument Systems

Purpose Process Documentation
Mechanism Control IE Command set document: MODS Instrument Electronics (IE) Command Set_ 1.9.1 (2017 Oct 4)
CCD Control ICs website: ??
Data Transfer CB Caliban v2.1 User's Manual
Environmental Monitor modsEnv none(!)
IMCS Agents   none

Telescope and Observatory Interfaces

Purpose Process Documentation
IIF Interface lbttcs description doc (where is this?), closest info seems to be in 2004 MODS Instrument Software Design
AGW server agw "client doc" - do you mean this one:, Interface Definition between off-axis AGW units and the Guiding Control System of the LBT ?
Data archive via CB and modsLogger none

Observing Software

Purpose Process Documentation
MODS GUI modsUI MODS Instrument Manual , see section 4.
Script engines execMODS, acqMODS script manual: ? MODS Observing Scripts
Image display dispMODS (aka modsDisp) none
Slit alignment modsAlign web manual: ??
Visualization tool modsView

Engineering / Support

Purpose Process Documentation
startup agent and run-time launcher mods1 and mods2 wiki (for usage) Instrumentation/MODSStartUp
mask management scripts modsMask Instrumentation/MODSSupportUtils#modsMask_Operate_the_Slit_Mask_S
Engineering interface iterm, imsTool, imcsTools  

Observing Preparation

Purpose Process Documentation
Script creation modsTools script manual: ;
Observation planning, parallactic alignment visualization
MODS science FoV visualization and guide star selection modsView
MODS Mask Design MMS

Data Reduction

Purpose Process Documentation
Basic 2D reduction modsCCDRed
Long-slit/MOS reduction modsIDL (April 2014)
I Attachment Action Size Date Who Comment
MODSSwArchitecture-screen.jpgjpg MODSSwArchitecture-screen.jpg manage 201 K 25 Jul 2017 - 17:09 UnknownUser MODS software architecture
MODSSystemOverview2017.pngpng MODSSystemOverview2017.png manage 118 K 27 Jul 2017 - 18:00 RichardPogge MODS Software System Overview (2017 Version)
MODS_IEB_System.pngpng MODS_IEB_System.png manage 480 K 04 Oct 2017 - 16:21 RichardPogge MODS IEB System Diagram
MODS_IUB_Schematic.pngpng MODS_IUB_Schematic.png manage 256 K 05 Oct 2017 - 14:29 RichardPogge MODS Instrument Utility Box (IUB) Functional Block Diagram
Topic revision: r9 - 05 Oct 2017, RichardPogge
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