RSView Supervisory Edition Installation Guide

14Using eventsThis chapter describes:• what events are.• setting up events.• using the Events editor.• creating an events component.• what the maximum update rate is.• starting and stopping event processing.About eventsEvents are expressions that trigger actions. Expressions are equations containing tagvalues, mathematical operations, if–then–else logic, and other built-in RSView ®functions. For information about using expressions, see Chapter 20, Creating expressions.Actions are RSView commands, symbols, or macros. An action could, for example,initiate a snapshot of tag values using the DataLogSnapshot command, or change a tagvalue using the Set command.14 • PlaceholderEvents are detected at RSView SE Servers only. Commands that are executed only at theRSView SE Client are ignored when issued by an event expression. For information about wherecommands run, see page A-4.An events component is a file that contains the definitions of one or more events. Anevents component can be run when an HMI server starts, or it can be run using theEventOn command, after the HMI server has started.Setting up eventsThese are the tasks involved in setting up events for an application:1. Create the events in the Events editor.2. Set the maximum update rate for the events component in the Events Setup dialogbox.3. Save the events component and give it a name. The file extension .eds is added by thesystem.14-1