Kramer Electronics COBRA R500A - Manual (Page 7)

Setup and Installation
5
4.3 Connections on the Video/Serial Transmitter
The single-port units with audio support video and serial signals over CAT 5
cable. The serial signal is 3 wire TX, RX, GND serial. Figure 3 shows the
Kramer Cobra transmitter with serial Transmitter connections, and Figure 4
shows the Cobra R500-2 Video-RS-232 receiver. See Appendix A for cable
pinouts of the Cobra R500-2.
Figure 3: Transmitter Connections
(Note: Both serial connection types are shown, but only one is used
depending on the model and settings).
Figure 4: Cobra R500-2 Video-RS-232 receiver Connections