User`s guide

145
In newer revisions the following rules apply:
*
A change of a quality attribute generates an event if EE = 1
*
A change of a quality attribute activates an event channel, a printout and/or
history logging if the activation is enabled (AE == 1, LD <> 0 or HE == 1) and
the activation criterion (AA, PA or HA) is "NEW VALUE" or "UPDATE".
*
In such activation, the changed attribute is reported as the value of CA pseudo-
attribute. If more than one attribute is changed at the same time, each change will
be reported separately in any order. For example, if OV changes from 0 to 1 and
SB from 1 to 0, two activations occur, one with CA == "BI", BI == 1 and SB ==
0, the other with CA == "SB", BI == 1 and SB == 0.
*
When the switch state (SS) or the substitution state (SU) of the object is changed,
the quality attributes are set to 0.
When "NO_QUALITY_ATTRIBUTE_SEMANTICS" is specified, the quality
attributes behave as in revision 8.4.2 and earlier.
4.1.5. Upgrading from revision 8.4.1
NO_ALIAS_CHECKING
Since revision 8.4.2 global variables are guarded against alias references. Status
SCIL_VARIABLE_ALIASING_ERROR is generated when aliasing rules are
violated.
When "NO_ALIAS_CHECKING" is set (either by the RC attribute of the
application or by REVISION_COMPATIBILITY function), alias checking is not
done. Turning on the switch by the RC attribute disables the checking of alias
referencing in the whole application. To disable the alias reference checking locally
in a program, use the REVISION_COMPATIBILITY function. The
REVISION_COMPATIBILITY function is described in the “Programming
Language SCIL” manual.
The arguments of method calls, as well as all the arguments of SCIL functions, are
passed by copy instead of reference. This degrades performance when text, bit
string, byte string, vector and list arguments are used.
If the base system will be used together with applications created with pre-8.4.2
revisions of the base system, e.g. using LIB 4.0.1, the revision compatibility switch
NO_ALIAS_CHECKING should be turned on.
MicroSCADA Pro
Installation and Administration Manual
SYS 600 9.2SYS 600 9.2
1MRS756115