Device CAL Requirement

On our a couple of our manufacturing lines we are installing a Windows 2003 Server (I/O Server) that will be gathering data from the manufacturing line PLC?s and passing it along to our HMI PC?s and Reporting Server. The PLC?s are like a robot where they don?t have a user and are specifically used to control and report on the manufacturing process. They do transfer information to the I/O Server, which in turn pushed the information up. The I/O Server is essentially multiplexing the down line devices, however, they are not “computing” devices. Would the require a Device CAL?

If they do require a CAL, do Printers, switches and WAP’s also require a CAL since they request and recive a DHCP address from a Windows Server?