# Create digital HMI tags

Digital tags will accept any numeric value. Zero will be written as False (0) and any non-zero number will be written as True (1). Use them to represent devices that have two states: on or off, such as switches, contacts and relays.

Important: | Do not point a digital HMI tag to a non-Boolean device tag.

Each graphic display can contain up to 1000 expressions or references to tags.

## See also

Create HMI tags

About data sources

Log tag data