Using CitectSCADA > Communicating with I/O Devices > Scheduled Communications > Reading from the scheduled I/O Device

Reading from the scheduled I/O Device

When the I/O Server initiates communication with the I/O Device, it immediately writes any queued write requests, then reads the I/O Device's tags. These values are then stored in a cache so that you can still access them between communications.

Note: Because the I/O Server reads tags on initiation of communication, the license point count is increased, even though some of the tags read may not actually be used.