OPCSDEFS(DOCS)	Optical Printer Control System	    OPCSDEFS(DOCS)

    NAME
	opcsdefs - OPCS definition file format description

    DESCRIPTION
	When the opcs system is first executed, the startup definitions file
	'OPCSDEFS.OPC' is loaded. This file contains commands that alter the
	initial settings of the sofware. During an OPCS session, other such
	'definition' files can be loaded via the LDEFS command, allowing users
	to modify the behavior of the motors as part of a production process.

	LDEFS also allows users to create small files which contain user's own
	preferences, without modifying the sacred OPCSDEFS.OPC file. It is
	recommended that settings be agreed apon by all those using the system,
	and once set up, the OPCSDEFS.OPC file not be modified, since users 
	will always assume the system's defaults will be the same. 

	The commands in OPCSDEFS files are different from the OPCS(OPCS) 
	commands, and even if names are similar, their usage and context will
	be different.

	OPCSDEFS commands should appear one command to a line. Comments may
	appear to clarify the commands and their intended purpose.

    DOCUMENTATION
	Use man -k OPCSDEFS: for a full list of the OPCSDEFS commands.
	With this list, you should be able to hone in on specific commands
	using man [command].

    TRICKS WITH DEFS FILES
    	People familiar with the IBM's operating system will be familiar with
	these capabilities...

	As with all DEFS file commands, you can execute motor definition
	commands from within the OPCS software by creating a small file,
	and the loading commands from it via LDEFS(OPCS)... In the following
	example, we switch back and forth between large and small counters:

	    ! echo bigcounters on > foo ! ldefs foo    # use big counters
	    ! echo bigcounters off > foo ! ldefs foo   # use small counters

	This 'trick' can be used with any OPCSDEFS commands, and uses the 
	operating system's ECHO command and 'reroute output' symbol (>) to 
	create the file FOO, which is then loaded as a file with the LDEFS 
	command. This technique CAN be used within a script or when entering
	commands manually.

	You can create multiline files from within a script as shown in this
	example using MSDOS's > and >> (append) symbols:

		! echo flog 2.0 >  foo
		! echo logcounters yes >>  foo
		ldefs  foo

	This technique can be programmed into run scripts, so defs file
	information can be changed on the fly.

	Here is another way to enter DEFS commands directly to the LDEFS 
	command from within the OPCS software:

		ldefs con          # Load the special MSDOS file CON...
		logcounters no     # which is really the keyboard (console)
		ppr a 400          # reading these commands from keyboard
		^Z                 # CTRL-Z and RETURN ends this mode..
		cam 12             # ..back to OPCS commands

	The 'ldefs con' technique works well for interactive typing, but 
	cannot be programmed into a script, since it always reads from
	the keyboard. Use the 'echo' technique listed in the previous example
	for programming DEFS commands into a running script.

	These techniques are actually standard ways of using the DOS operating
	system, and are not particular to just the OPCS software.. they can be
	used by any program running under MSDOS that properly supports the
	operating system.

	Users not familiar with these techniques should learn them only if
	they think they might need them. At very least, operators should 
	be aware of this capability.

    FILES
	\USR\BIN\OPCS.EXE	- the OPCS system software executable
	OPCSDEFS.OPC		- the 'start up' definition file
	*.OPC			- other opcs definition files
	*.RUN			- run scripts
	\USR\CATMAN\OPCS\*	- online documentation pages

    SEE ALSO
        OPCS		- the opcs system in general overview
	OPCSETUP	- setting up opcs software for the first time
	OPCSHARDWARE	- hardware specifics (wiring, etc)

    ORIGIN
	Gregory Ercolano, Los Feliz California 11/29/89
© Copyright 1997 Greg Ercolano. All rights reserved.