The Sony HD Camera models HXCU-100 / HDCU-1000 / HDCU-1500 has a 2-wire and 4-wire mode.When connecting any camera CCU to a Clear-Com matrix or PL system we recommend that you set the CCU into 4-wire mode 
Why?  The camera bridges our 200 ohm line well below the 18K ohm we want to see.   One camera is not a problem --- add a second and third... the connection loads the line and brings the audio levels down to a "un-usable level"
The solution?   All broadcast quality  cams --SD or HD -- offer a 4 wire option....  Clear-Com always recommend that you use the 4wire mode setting on your camera -- four (4) wire is superior 
For PL interconnection - set the CCU into 4-wire - use a good quality 2/4 wire adapter like the Clear-Com IF4W4 unit - wire each CCU directly into one port of the IF4W4 unit 
For Matrix interconnection-set the CCU into 4-wire mode- wire the each CCU directly to one port of the matrix.
This is oursuggestion for connection to a Matrix (MVX) 4-wire port
Matrix (MVX) RJ45 Port                    CCU 25 pol D-SubPL ENG
3 (Audio Receive+)  <---      pin 1 (Audio Sent X)
4 (Audio Send+)      --->      pin 4  (Audio Receive X)
5 (Audio Send-)       --->      pin 5  (Audio Receive Y)
6 (Audio Receive+)  <---      pin 2 (Audio Sent Y)
Screen                      --->     pin 3  (Ground)

PL PROD
3 (Audio Receive+)  <---      pin 14 (Audio Sent X)
4 (Audio Send+)      --->      pin 17  (Audio Receive X)
5 (Audio Send-)       --->      pin 18  (Audio Receive Y)
6 (Audio Receive+)  <---      pin 15 (Audio Sent Y)
Screen                      --->     pin 16  (Ground)