Datasheet

Fig Status attribute of enumeration type
Normally you also add attributes for the channel objects in the card class, but as the USB I/O device
is so flexible, the same channel can be configured as a Di, Do or Ai channel, we choose not to place
the channel objects as attributes. They will be configured as individual objects and placed as
children to the card object in the root volume.
USB I/O contains a watchdog that will reset the unit if it is not written to within a certain time. We
also add the attribute WatchdogTime to configure the timeout time.
When a class is saved for the first time, a Template object is created under the $ClassDef object.
This object is an instance of the actual class where you can set default values of the attributes. We
state Specification, insert an URL to the datasheet, and set Process to 1. We also set
MaxNoOfChannels to 21, as this card has 21 channels.