Topic: DMD0427
DEBOUNCE - Reduce Discrete Input Chatter
The Reduce Discrete Input Chatter (DEBOUNCE) instruction is used to remove the electrical noise from the input logic of a rung of ladder logic. Electrical noise (also known as contact bounce) is typically seen as very short, high rate, oscillations that occur when the electrical contacts used in a mechanical switches or push buttons are actuated. Because this electrical noise can result when the electrical contacts are closed or opened, the DEBOUNCE instruction has a programmable “OFF to ON” Time Delay, and an “ON to OFF” Time Delay (both in milliseconds). The delay times should be set to values longer than the amount of time the electrical noise occurs.
Parameters:
Note: Use the F9 key to open the Default Element Selection Tool (the Element Picker or the Element Browser) or use the Down-Arrow key (Auto-Complete) on any parameter field to see a complete list of the memory locations that are valid for that parameter of the instruction.
Set Delay is the amount of time in milliseconds the input logic must be ON before the instruction will turn ON the specified Debounced Bit. This can be any constant value from 0 to 32766 or any numeric location containing a value in that range.
Reset Delay selects what to do with the output bit when the input transitions from ON to OFF.
Use Reset Delay is the amount of time in milliseconds the input logic must be OFF before the instruction will turn OFF the specified Debounced Bit. This can be any constant value from 0 to 32767 or any numeric location containing a value in that range.
If Do Not Reset is selected this instruction will never turn OFF the Debounced Bit. Once this instruction turns the bit ON, some other mechanism (a different instruction, an HMI, etc.) will have to turn OFF the Debounced Bit.
Debounced Bit specifies the bit location to turn ON and OFF. This can be any writable Bit location.
Status Display:
The yellow triangle in the upper left corner indicates this is a Multi-Scan instruction.
See Also:
DEBOUNCE - Reduce Discrete Input Chatter
Related Topics:
Example:
