Teledyne 440, System Manual, Page: 56 / 256

4 – Electrical Installation
4-10 © Teledyne TSS DPN 402196 Issue 4.1
cation between the SDC and the sub-sea installation passes through the relevant
SDC serial port.
Communication lines between the SDC and the sub-sea components are opto-isolated at both ends.
The following tables show the connections that you must make between the SEP and the SDC for each
of the three communication methods. See
section 4.1.3 "Power Supply Pod" on page 4-3 and Table 4-
2 for details of the connections that you must make between the SEP and the ROV electrical
distribution system.
To use current-loop communications you must reserve either one or two conductor pairs in the ROV
umbilical for the exclusive use of the 440 System. The System includes a cable that you should use to
connect the ‘COMMS FROM SEP’ port on the SDC to the twisted pairs in the ROV umbilical. The cable
has a 15-way D-type connector for connection to the SDC ‘COMMS FROM SEP’ port, and open tails
for connection to the umbilical at a junction box.
Previous versions of the SDC required a jumper cable to be fitted between the 15-way D-Type and
COM1 of the SDC. However, the SDC10 internally connects the 15-way D-Type to COM1 and removes
the requirement for the jumper cable.
Table 4-5: Power and Communications cable – 2-wire current loop connections
SEP Power/Comms
port
Pin number
Function
SDC ‘COMMS FROM POD’
(15 way) pin connection
4
5 CL-
CL+

ROV umbilical
3
4
Table 4-6: Power and Communications cable – 4-wire current-loop connections
SEP Power/Comms
port
Pin number
Function
SDC ‘COMMS FROM POD’
(15-way) Pin connection
4
5 CL+ Input
CL- Input

ROV umbilical (Tx in
SDC)
3
4
6
7 CL+ Output
CL- Output (Tx in SEP) 5
6
Table 4-7: Power and Communications cable – RS232 connections
SEP Power/Comms
port
Pin number
Function
SDC ‘COMMS FROM POD’
(15-way) Pin connection*
4
5 Tx output from
SEP
Rx input to SEP

Data cable
3
4
6 Common 5
The 15-way D-Type labelled “COMMS TO SEP” is internally connected to the Panel PC COM1. Hence all communica-
tions protocols, including RS232, must use the 15-way D-Type.