Filter Time Constant
AI Notes
Via the SX Tool
The high limit is at Item HIAn (RI.91, RI.99, RI.107, RI.115, RI.123, RI.131, RI.139, and RI.147), the low limit is at Item LOAn (RI.92, RI.100, RI.108, RI.116, RI.124, RI.132, RI.140, and RI.148). These Items may also be set by a Supervisory System and will always be set by
a
The differential on alarm limits is adjustable with Item ADFn (RI.93, RI.101, RI.109, RI.117, RI.125, RI.133, RI.141, and RI.149).
The Filter Time Constant Ts (seconds) is used to filter out any cyclic instability in the analog input signals. The calculations are:
FVt =
Where: | FVt | = Filtered Analog Value at current time | |
| = | Filtered Analog Value at previous poll | |
| AIt | = | Actual Analog Value at current time |
A value of “0” disables the filter.
Via the GX Tool
Select XTn, AIn, and Data. At the “Filter Constant (sec)” field, enter a number within the recommended range 0 to 10.
Via the SX Tool
The Filter Time Constant is entered at Item FTCn (RI.94, RI.102, RI.110, RI.118, RI.126, RI.134, RI.142, and RI.150).
1.When the
2.Analog input values can be read via the SX Tool at Item AIn (RI.12 to RI.19).
3.Analog input alarm status can be seen via the SX Tool at Item AIS (RI.11), Bit X1, X3....X15 for high alarm condition and X2, X4....X16 for low alarm condition.
4.Configure all AIs as Active or Passive, whether they are used or not. A configured AI is shown by a thick bar to the left and right of its selection box.
