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Appendix A
Programmable Function Keys and LCM
Notice: Only the UC-7420 and UC-7410 support LCM and Keypad functions
In this appendix, we describe an internal service that is built around the function keys. This
mechanism is designed to aid your applications in accessing these I/Os, but without needing to
understand the complexity of I/O controls. Though this service gains controls on these
programmable I/Os, it does not prevent you from developing them. Instead, we provide this
mechanism for you to make it easier for you to develop your applications.
This mechanism consists of a function key agent and a configuration utility. The agent operates
based on five lists of pre-defined action items. Each list corresponding to a function key links a
cyclic series of action items (10 at most) to be executed. The header item of this list maps directly
to the first hit of the function key and then the next items follow. At the end of the list, the next hit
circles the action back to the first item. A list without items comes with no action to be executed.
Each action item can be in plain text or an application that you develop. The former is normally
used for a reminder message, such as a manual for operating the function keys. The latter can be
an LCM application. Nevertheless, this application is required to use the LCM APIs in our library
mxdev.lib
to transmit the variable text to the LCM.
We have used this mechanism to implement an application on function key F1. When the key is
pressed, the agent triggers this application to gather information and then displays the information
on the LCM. The information includes the firmware version, network address settings, and current
memory usage of the computer. These are particularly useful when you forget network information
and have difficulties connecting to the computer. In addition, it provides an alarm system
indicating the availability of your memory resource in the computer by preventing you from
overusing your memory or losing data.
To assist you in using this function key service for I/Os, the web-based management system also
implements a utility to configure action items. To configure a plain text item, follow these steps:
