Softkey

image\block_softkey_sn.gif

Short description

This SFB provides the action of a mechanical pushbutton or switch.

 

Connection

Description

Input En

Output Q is set with a 0 to 1 signal transition at input En (Enable) and if in addition, 'Status=On' has been confirmed in configuration mode.

Parameter

Switch: Sets either a momentary pushbutton action for one cycle (On) or a switching action of the function (Off).

Status: On or Off state that is applied in the initial cycle after program startup, if retentivity is not set.

Retentivity set (on) = the status is retentive in memory.

Output Q

Output Q remains set 1, as long as En=1 and the status at the parameter Type = Switch and Status = On.

Output Q is set for the duration of one cycle if EN=1. Switch = On (momentary pushbutton) and Status = On.

Factory state

The default of the Switch parameter is switching action.

Timing diagram

image\block_softkey_diagram_sn.gif

Description of the function

The output is set when input En is set and the 'Status' parameter is set to 'On' and confirmed with OK. This action is performed irrespective of a configured switch or pushbutton function.

The output is reset to '0' in the following three cases:

Particular characteristics to be noted when configuring

The softkey can be used both with momentary pushbutton or switching action. At the status parameter you can define the on (actuated) or off state for the switch/pushbutton.

If the softkey is assigned a pushbutton action, the output is always set for the duration of one cycle with a 0 to 1 transition at input En when the pushbutton is in on state, or if the pushbutton state changes from Off to On when En=1.

 

Overview