An Attribute Motor can drive Tango attributes like a motor. In the following it is explained how the undulator gap is made an attribute motor.
This is how an attribute motor is introduced to Online:
<device> <name>gap</name> <type>type_tango</type> <module>motor_tango</module> <device>p03/attributemotor/gap</device> <control>tango</control> <hostname>haspp03:10000</hostname> </device>