F182_FILTER

Filter processing is executed for specified bits and output bitwise. The instruction can be useful to negate the effects of bounce, e.g. for a switching device.

Parameters

Input

s1_InputData (WORD, INT, UINT)

Input data whose bits will be filtered according to the input mask

s2_InputMask (WORD, INT, UINT)

Input mask which specifies which bits will be filtered

s3_FilterTime (WORD, INT, UINT)

Specifies the minimum off- and on-time in ms

Output

d_OutputData (WORD, INT, UINT)

Filtered data

Remarks

• Instead of using this F instruction, we recommend using the corresponding FP7 instruction: FP_DEBOUNCE

• When the system detects a trigger's rising edge, all the bits of the input specified by s1_InputData are output directly in d_OutputData and the effects of bounce are not prevented. A scan time error may occur during filter processing, for a maximum of 1 scan.

• For bits stored in the area specified by s1_InputData a debouncing is executed if the resulting value for s2_InputMask is "1". The result of the debouncing operation is output to d_OutputData. The debouncing time is defined via s3_FilterTime (0 to 30000ms). If s2_InputMask is "0" no debouncing takes place and the corresponding bit at s1_InputData passes unchanged to d_OutputData.

• In the following figure, the bits in d_OutputData and their values will be the same as s1_InputData after the filter time has elapsed or, for example, if no masking takes place, e.g. s2_InputMask is assigned the value 0.

  

  1.  (1) s1_InputData
  2.  (2) s2_InputMask
  3.  (3) s3_FilterTime (if InputMask =1)
  4.  (4) d_OutputData

Time chart

• 1 (16#0001) is assigned to s2_InputMask is , i.e. bit 0 will be filtered, the other bits will not be filtered, and the value assigned to s3_FilterTime is 500ms.

  

  1.  (1) Bit 0 of input data
  2.  (2) Bit 0 of filter result
  3.  (3) Data is initialized when the system detects the trigger's rising edge.
  4.  (4) The instruction does not operate while the trigger is OFF.

• 0 (16#0000) is assigned to s2_InputMask is , i.e. bit 0 to F will be not filtered

  

  1.  (1) Bit 1–15 of input data
  2.  (2) Bit 1–15 of filter result
  3.  (3) Data is initialized when the system detects the trigger's rising edge.
  4.  (4) The instruction does not operate while the trigger is OFF.

Error flags

sys_bIsOperationErrorHold (turns to TRUE and remains TRUE)

if the filter processing time specified by s3_FilterTime is less than 0 or greater than 30000.

sys_bIsOperationErrorNonHold (turns to TRUE for one scan)

if the filter processing time specified by s3_FilterTime is less than 0 or greater than 30000.