Q. How can I access data supplied by a real-time data server in an AVS/Express module and how do I use that data in AVS/Express?

A. To get the data, you can use the OM routine, EVadd_select to add an event callback handler. The callback function is invoked at a specified time, for example, when input data is available on a file descriptor or when the Object Manager is idle. This function would fetch the new data available from the server.

To use the data, you typically change the node_data values in an existing Field. You either replace the values with your new data, thereby refreshing the display, or you can "cycle" the data, replacing just the last n values with the new values and bumping all the others down in the values array. You can also use the new data values to create a brand new Field and display it along with the existing one.

The loop module in AVS/Express is implemented using EVadd_select (and its companion function, OMdel_select). Source code for loop can be found in loop.c in the "gmod" subdirectory of your AVS/Express install area.