Cloud Electronics 46-120 - CDI-46 - Manual (Page 26)

CDI-46 Installation and Setup Guide V1.0 26
Using the CDI-46 as an Ethernet-to-serial bridge
The CDI-46 may be used as an Ethernet-to-serial bridge. Many AV control systems now transmit serial data strings in TCP/IP
format via an Ethernet interface, rather than from an RS-232 port. However, some equipment – projectors and other display
devices, for example – only accept serial control via an RS-232 port.
The CDI-46 is able to receive serial data at the Ethernet port and re-transmit it from the RS-232 port, and thus act as an
Ethernet-to-serial converter or bridge.
46-120
RS-232
Serial Port
Ethernet
This function uses the CDI-46’s virtual CDI port, whose address has the default value of 4998. If the controlling device is only
able to support remote ports in a certain address range (i.e., not including 4998), the port address can be changed on the
Communications page of the browser interface (accessed from Config > Network).
Cable lengths
RS-232 serial communication can use either shielded or unshielded cable. The longest cable run that can be practically used for
error-free operation in a given installation will depend on several factors: cable type, the baud rate used and the amount and
type of electrical noise present in the cable’s vicinity.
A realistic figure for maximum cable length is 250 ft. (76 m) using good-quality shielded cable and 100 ft. (30 m) using unshielded
cable, at 9600 baud (the most common data rate).
However, the figure may be higher or lower in a particular installation. Lowering the baud rate will permit significantly longer
cable runs to be used.