Basler Electric BE1-851 - Manual (Page 151)

Table 7-4. Label Settings for OUTPUTS
Setting Range/Purpose Default
Label
1 to 10 characters.
User label to replace default label. VOx_LABEL
(where x = 1, 2, 3, 4, 5, or A)
True State
1 to 7 characters.
User label to replace default label.
TRUE
False State
1 to 7 characters.
User label to replace default label.
FALSE
Table 7-5. Label Settings for 43 SWITCHES
Setting Range/Purpose Default
Label
1 to 10 characters.
User label to replace default label. SWITCH_x
(where x = 43, 143, 243, or 343)
True State
1 to 7 characters.
User label to replace default label.
TRUE
False State
1 to 7 characters.
User label to replace default label.
FALSE
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 will not be available to a numerically higher virtual
output until the next processing interval. Logic is evaluated every quarter 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. Caution
should be taken with normally closed contact logic because there are no shorting bars to maintain the
closed condition if the draw-out assembly is removed from the chassis. In applications where a normally
closed output is needed even when the electronics are removed, a normally open contact from the relay
can be used to drive a low-cost auxiliary relay. The normally closed output of the auxiliary relay will
maintain the closed output when the draw-out assembly is removed from the case. Alternately, an
external switch can be used to short across a normally closed relay output when the draw-out assembly is
removed. Extra care is required to ensure that the switch is closed before removing the draw-out
assembly and that the switch is open after the relay is placed back in service.
Several links between the programmable alarm functions 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 alarm reporting function.
9289900990 Rev R BE1-851 BESTlogic™ Programmable Logic 7-11