When configuring your Pulse Survey, you have the option to have all your employees participate, or just a specific subset.
This is done in the Participants section of Pulse setup. If you have already launched your Pulse, access your Pulse setup by navigating to Settings and selecting Change configuration.
All Employees Participate
If you would like all your employees to be Pulsed, select All employees in the Participants section of the Pulse setup
Subset of Employees Participate
If you would like only a particular subset of your employees to be Pulsed, select Specific employees in the Participants section of the Pulse setup. Then select the filter to select employees you'd like to Pulsed based on default and custom user attributes.