Honeywell HC900, Reference Manual, Page: 58 / 456

Function Blocks
AI Function Block
44 HC900 Hybrid Control Designer Function Block Reference Guide Revision 11
2/07
Parameter Index # Parameter Description Value or Selection
High Range
Value
6
For Linear Inputs Only - output value
that corresponds to 100% input value.
For example:
Actuation Input = 4-20mA
Process variable = Flow
Range of Flow
= 0 to 250 gal/min
High Range Display Value = 250
Low range Display Value = 0
Then 20mA = 250, 4mA = 0
Enter a value:
± 99999 to ± 99999
Low Range
Value
7 For Linear Inputs Only - output value
that corresponds to 0 % input value
For example: See “High Range
Value”. Enter a value:
± 99999 to ± 99999
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
LINEAR
OUT = Value set at “Low range value”
field.
T/C or RTD
OUT = Value of Low range implied by
input type.
Click on Radio
button to select
Upscale LINEAR
OUT = Value set at “High range
value” field.
T/C or RTD
OUT = Value of High range implied by
input type.
Click on Radio
button to select
Burnout
Check
N/A
Burnout check enable
(Thermocouples only) Click on block to
select or deselect
Bad Channel
Detection
N/A Check this to generate a hardware
failure diagnostic if a bad AI channel
is detected. If unchecked, a
diagnostic will not be generated,
which may be desirable for inputs
used for monitoring only. Click on block to
select or deselect