Basler Electric BE1-700 - Manual (Page 179)

BESTlogic
™ APPLICATION TIPS
When designing a completely new logic scheme, logic evaluation order should be considered. Contact
sensing inputs are evaluated first, then the function blocks, and then the virtual outputs. VO15 is
evaluated first and VOA is evaluated last. If a virtual output is used in a logic expression to control another
virtual output, the virtual output used in the expression should be numerically higher. Otherwise, a logic
expression for a numerically smaller virtual output won't be available to a numerically higher virtual output
until the next processing interval. Logic is evaluated every ½ cycle.
When designing custom protection schemes, avoid confusion by maintaining consistency between input
and output functions in the custom scheme and the preprogrammed schemes.
OUT1 through OUT5 have normally open contacts (coil is de-energized). Normally open contacts can be
used as normally closed outputs by inverting the logic expressions that drive them. Inverting an output
logic expression causes the coil to be energized with the contacts closed in the normal state.
Several links between the programmable alarms function and BESTlogic programmable logic allow alarm
functions to be used in a logic scheme and programmable logic functions to be used in the alarm
reporting function.
Programmable alarm settings for Major, Minor, and Logic alarms drive BESTlogic variables ALMMAJ,
ALMMIN, and ALMLGC. These variables can be used in logic expressions to control logic when an alarm
is active.
Virtual outputs VO13, VO14, and VO15 are driven by BESTlogic expressions. These three logic variables
are also available in the programmable alarm function. Virtual outputs can also be assigned user
programmable labels (described previously). With this feature, a logic condition can be designed and
used for an alarm. The virtual output label would then be reported in the Reporting and Alarm functions.
9376700990 Rev M BE1-700 BESTlogic Programmable Logic 7-11