Siemens SIPROTEC 7SJ62 Manual page 611

Figure A-58
1) for 7SJ64 port D
2) for 7SJ64 optionally port C or port D
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
Half-duplex operation with two RTD-Boxes, above: optical design (2 FOs);
below: design with RS 485
Appendix
A.3 Connection Examples
611