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