MRV Communications EM316E3 - Manual (Page 10)

Fiber Driver
EM316E3 & EM316E3SF
P/N: 1226006-001, REV_L PAGE 10
Switch LPBK/NORM is set to OFF
Switch LPBK/NORM is set to OFF
Loop Back Control: By NMS command or manually by a switch
Loop back can be forced regardless of management by turning switch 1 MAN/NMS to ON and
switch 3 NORM/LPBK to ON.
NOTE: It is also possible to configure an external loop, either on E3 side or the fiber side, the
switch LPBK/NORMAL should remain in NORM position since the card is in its Normal mode.
For external Fiber optic loop back, connect a fiber between RX SC connector and TX SC
connector see (fig 3a). For external E3 loop back connect a coax cable between RX BNC
connector to TX BNC connector (fig 3b)
Loop back on
Fiber side
E3 side
Coax to near DTE
Fiber side
To far EM316E3
Loop back on
E3 side
Fig. 3a: External loop back on fiber optic
Fig. 3b: External loop back on fiber optic