Button Objects — Pushbutton, Switch, Radio Button, Step Switch, and Tri-state Switch

 Topic: CM187

This topic deals with Button objects that cause one or more discrete tags to change state.

The Key Button object that appears in the Button section of the object list is documented in the Key Button Object topic.

The Button objects features include:

  • Password protection
  • Visibility
  • Sound options
  • Press Delay

Some buttons include a Release Delay configuration.

Press Delay will wait the configured delay time before the Tag changes to ON after the button is pressed. Release Delay will wait the configured delay time before the Tag changes to OFF after the button is released. Select the Delay Time from the drop-down list by clicking on the down arrow located to the right of the Delay Time field.

Details on configuring Passwords for Objects and Screens are available in the Password topic.

Visibility may be configured using a discrete tag or a numeric tag. The object will be visible when the tag or tag conditions are true. Object visibility may be useful in your project but it also has a significant cost in terms of CPU resources and noticeably affects screen update rates.

The generic Pushbutton, Indicator Button or Switch can be configured to operate as:

  • Toggle: The Toggle choice will Toggle the Pushbutton operation between ON and OFF each time the Pushbutton is selected (pressed).
  • Momentary On: Causes the Pushbutton to be ON while the Pushbutton is pressed. As soon as the button is released it returns to the OFF state.
  • Momentary Off: Causes the Pushbutton to be OFF while the Pushbutton is pressed. As soon as the button is released it returns to the ON state.
  • Set On: Causes the Pushbutton to be set to the ON state when the Pushbutton is pressed. Once it is set to ON it remains ON until a separate device, such as another Pushbutton or signal from the PLC, turns it OFF.
  • Set Off: Causes the Pushbutton to be set to the OFF state when the Pushbutton is pressed. Once it is set to OFF it remains OFF until a separate device, such as another Pushbutton or signal from the PLC, turns it ON.

The Radio Button may use Bit of Word to identify which button is set ON, or it may use multiple discrete tags. If Bits of Word are configured, the Radio Button may have 2-16 options. If Discrete tags are configured, the Radio Button may have 2-8 options.

The Step Switch Object works like a Mechanical Step Switch. With this type of Switch, each time the Step Switch is pressed, each of the assigned Tag Names cycle one at a time from the Off position to the On position. Only one assigned Tag Name is On at a time.

The Tri-State Switch Object consists of a set of three pushbuttons that allow to configure the first button to the left as a Reset that turns the other two buttons Off, and configure the other two buttons with individual Tag Names.