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
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...
Telescope and Observatory Interfaces
Engineering / Support