THIRD-PARTY FTDI APPLICATION MODULES
As discussed previously, the FTDI Third-Party modules enable a system to extend its functionality. The module plugs into the system’s USB host port and requires only an FTDI driver to be installed to programmatically access the module’s functionality. A representative sample of modules is listed in Table 44-1 and display in Figures 44-9 through 44-12.
The data acquisition, relay, and Elexol modules all implement a simple textual command protocol as described in their datasheets. Datasheets for the DLP modules can be obtained from the FTDI web site. The Elexol datasheet URL is www.elexol.com/Download/documents/USBIO24Rds1.pdf.
Now look at the DLP-IOR4 Relay Module in some detail. It has four SPDT latching relays, which means that each relay can be switched (and stays there) to take one of two inputs (A or B) to its output. The relay terminals do not connect ...