HDCD8TP 8-way bi-directional distribution units give users the capability of expanding the number of receivers (e.g., PTZ receivers) in a system. The input to the HDCD8TP can be either an RS-485 or RS-232 (PC) controller. Each output is capable of transmitting control data via daisy chain wiring to 32 RS-485 units. There is an RS485 loop-through connection and RS-485 termination links to enable several units to be connected in a daisy chain wiring configuration. These bi-directional distribution units can be used to extend the distance for controlling RS-485 receivers. If the required distance between RS-232 or RS-485 controller and the receiver is greater than 4,000 feet, this unit can be installed to extend the distance to a receiver an additional 4,000 feet. They can also be used for applications that require a “star-wiring” configuration. In a star wiring configuration, each output on the HDCD8TP is connected to a single receiver. Multiple HDCD8TP units can be daisy chain wired together to provide the required number of outputs for each receiver in the system. The HDCD8TP has three front panel LED indicators—one power indicator and two data indicators—that designate the direction of transmission to or from the receivers.