Access to NSTX EPICS Data

The EPICS system is part of the NSTX Engineering Controls system. EPICS interfaces with NSTX's Engineering Subsystems, such as water system, motor generator, etc...  via CAMAC, PLC's, and PC's. The Engineering Controls are behind a network firewall to protect the subsystems from unauthorized control.  An EPICS gateway has been installed to permit read-only access to the EPICS data from PPPL's  general (office) network.    A diagram of the NSTX EPICS data access configuration is shown here. There are a variety of methods now available to access NSTX EPICS data and view  NSTX's current conditions. These are described below.

Using a PC

• web browser
• medm, alh, probe
• Archive Viewer (trend data)
• LabVIEW
• 'DOS' commands.
• Available from the collaboration but not tested: IDL, C, java, perl, python, fortran, tcl/tk
• With an X11-server (eXceed, cygwin/X) you can access programs on the unix cluster (see below).

Using a Macintosh

• web browser
• Archive Viewer (trend data)
• With the MacOS X native X11-server you can access programs on the unix cluster (see below).  This has worked on a miniMac, but there have been 'invisible fonts' problems on other mac platforms.
• MEDM is supposed to compile and run on a Macintosh OS X  platform, but I haven't put much effort into that.  Contact me psichta@pppl.gov if you're interested in using that. 

From a Linux cluster (e.g. portal)

• medm, probe
• IDL program access
• shell/system calls
• C Programs
• Available from the collaboration but not tested: perl, fortran, java, python, tcl/tk

From the VMS cluster

• file NSTXEPICS.TXT .This file is updated every 15 seconds. This is a depecated solution.  Use IDL functions instead.
• web browser
• IDL program access (currently can only read from epics IOC/CA_Servers)
• Compiled but not tested at PPPL: C Programs
• Hope to develop EPICS 'writes' (puts) soon.

From MDSplus

Trended Data

• About 300 process variables from several EPICS IOC's are trended (variables are sampled once per minute, 24x7) and stored in MDSplus.
• The data is stored in the ENG_TREND tree.
• The 'shot' number is in YYYYMMDD format and covers one 24-hour period.

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Page edited  27JAN2005   by Paul Sichta [psichta@pppl.gov]