Nevion AV-3G-XMUX - Manual (Page 38)

GPI alarms 38
AV-3G-XMUX User Manual Rev. B
9 GPI alarms
Only three alarms are present on the 8P8C jack (RJ45) connector as four of the pins are used for
the RS422 data port. The three alarms are:
1. GPI1 Status (negative logic) This alarm will be inactive if:-
• The power is not present in the module.
• The FPGA firmware is invalid.
• The DWDM laser option has failed.
1. GPI2 Video signal lost
2. GPI3 Laser failure (DWDM option not fitted)
The alarm signals are open collector transistor switches. An active condition means that the tran-
sistor is conducting. The Status alarm should always be active during normal operation.
9.1 Laser kill GPI3 input
GPI3 is used as a GPI input to kill the laser output when the DWDM laser option is fitted. Con-
nection of the pin to 0V will switch off the laser. The pins of several modules may be connected
together to kill all of the lasers going into a multiplexer filter.