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Function Blocks
RAI Function Block
Revision 11
HC900 Hybrid Control Designer Function Block Reference Guide
305
2/07
Parameter
Index #
Parameter Description
Value or Selection
Remote C/J
N/A
Set FAIL pin ON if RCJ value outside
limits (-30 to 90 ºC)
Click on block to
select or deselect
Disable
Channel
Output Value
8
The output value when the AI channel
is disabled. Disable = ON
Enter a value
Default = 0
Filter Time
(sec)
2
A software digital filter is provided for
the input designated to smooth the
input. You can configure the first
order lag time constant from 1 to 120
seconds. 0=no filter
Enter a value:
0 to 120 seconds
Bias
3
Bias is used to compensate the input
for drift of an input value due to
deterioration of a sensor, or some
other cause.
Enter a value:
±9999 to ±99999
Failsafe Use
Value
N/A
Use the User value entered in the
appropriate field.
Click on Radio
button to select
Failsafe Use
Value field
4
The output value to which the output
will go to protect against the effects of
failure of the equipment, such as, fuel
shut-off if there is loss of flame in a
furnace, or a sensor break.
Enter a value in
Engineering Units
±9999 to ±99999
Downscale
N/A
OUT = Value of Low range implied by
T/C input type.
Click on Radio
button to select
Upscale
OUT = Value of High range implied by
T/C input type.
Click on Radio
button to select
Burnout
Check
N/A
Burnout check enable
Click on block to
select or deselect
Failsafe rules
If the controller is unable to access the physical channel or the sensor is faulty, and:
•
If Failsafe is “Use Value”
Then OUT = Configured Failsafe value
•
If Failsafe is enabled and downscale
Then OUT = Low Range Value of T/C input type
•
If Failsafe is enabled and upscale
Then OUT = High Range Value of T/C input
type