C-more is designed to support the HID specification for external USB devices. This gives users the ability to connect various input components to a C-more panel for additional capability and expansion possibilities.
We've tested C-more with several HID devices, such as external keyboards, bar code readers and card scanners. With v6 of the software we've added full mouse support - so you can control an on-screen curser with a standard mouse or trackball. While we can't guarantee that C-more will work with every third party product available, we're committed to supporting the HID specification. Let us know about HID devices that you are using successfully, or if you're having trouble, please contact tech support.
Other than mouse or trackball, the C-more objects that accept input from these input devices are the "Numeric Entry", and "Text Entry" objects. We will be providing additional object support for HID devices in the future, check back here for more information.
More information is available here.
And here is an excerpt from that site:
The HID class consists primarily of devices that are used by humans to control the operation of computer systems. Typical examples of HID class devices include: