Macalc Abstract

Usage :  MACALC is the Java Open Access Client (OAC) process which
	 supports user-defined calculated devices whose values are
	 derived from the readings of other devices.  Devices are
	 defined by the use of a web-based expression editor
	 (http://belobog.fnal.gov:8000/CompositeDevices/index.jsp?).
	 Use of this editor requires an account which can be requested
	 from Timofei Bolshakov.  MACALC device readings are updated
	 at a 1 Hz rate.  You can view log files for MACALC in the
	 directory 'daesrv\\engines\files\oac'.  MACALC runs on DUE39.

	 MACALC's defining expression really looks like an equation.
	 You enter an algebraic expression, using ACNET device names
	 as the variables.  Several mathematical functions including
	 those in the Java Math class (e.g. sin, cos, tan, sqrt, ceil,
	 abs, exp, log,...) and others including cosh, sinh, tanh, min,
	 max, average, sum, and condif are all implemented. Some examples:

	    * (D:95WST + D:95WRT)/2
	    * 0.463 * ( A_FLOWPC - A_FUPPC )
	      (We have adopted the convention in use in other places that
	       specifying the device name using an underscore (_) in place
	       of a colon means read the setting.)
	    * condif((A:T109SM @ 0.0), (10000.0*A:IBMAV/A:T109SM),0.0)

	 condif is a conditional function. If the first argument is true,
	 it returns the second argument, otherwise the third.
	 condif(boolean condition, value1, value2) is the equivalent of
	 the C/Java notation "(boolean condition)?value1:value2;".

	 Instead of '>' we use '@' because '>' is otherwise used for array
	 notation.

	 A single verticle bar '|' is used as the binary OR. A single
	 ampersand '&' is used as the binary AND.

	    * condif((((a:ibeam @ -200.0) & (a:ibeam< -0.05)) |((a:ibeam @ 0.05) &(a:ibeam < 200.0))),A:EMITH/a:ibeam,0.0)

	 If an MACALC device has a status property, it's expression must only
	 contain logical arithmetic operations.  Only the following logical
	 functions are available: rightShftBytes(device,Nbytes),
	 leftShftBytes(device,Nbytes), logicalOr(A,B),logicalAnd(A,B),
	 logicalXOR(A,B), and byteNumber(device,N).

	    * logicalOr(I:LCWCUB:0:1,leftShiftBytes(I:LCWCUB:10:2,1)) 

Restart: MACALC is restarted when its DAE is restarted.

Keeper: Dennis Nicklaus

OAC Node: dce10

Now: Mon Oct 6 22:12:00 2008