A certain network of osn 7500 needs to be synchronized via an external clock. The external clock equipment is oscilloquartz 5581C . When a cable is connected with 120 ohm,interface from external clock source DB9 port to OSN 7500 AUX board clk4 port, OSN does not detect the
external clock and T2000 reports synchronous source unavailable.
EXT_SYNC_LOS on both T1EXCSA boards
1> The oscilloquartz port is checked via LED and it is foud to be ok
4> The aux board is also checked to be fine.
3> Various different combinations of cables are tried but still OSN AUX board failed to detect G.811 clock.
Finally the cabling configuration mentioned in the attacched file is used and the cable is connected to clk3 of EOW board instead of AUX board.
The clock is now detected successfully as G.811 and EXT_SYNC_LOS alarm dissapear.
Actually the clk3 port of EOW corresponds to the External clock source 1 in T2000.
The pin configuration of osn 7500 AUX clk4 port is
1 Receiving -
2 Receiving +
4 Sending -
5 Sending +
And the pin configuration of Oscilloquartz 5581C DB 9 out port is
A cable is made acording to the above specifications but it doesnt work.
The oscilloquartz has never been connected to OSN 7500 before so :
1> Maybe the oscilloquartz is not transmitting clock.
2> Maybe the pinout of the cable are wrong.
3> Maybe only out 1 and gnd of oscilloquartz are required for the clock.
4>Maybe the clk port of aux board is faulty
5> Maybe the Aux board is faulty.
The first step in connecting an external clock is to verify the pin configuration of the External clock source and the OSN port.
Always use the CLK3 port against the External clock source 1 in T2000 and use the AUX clk4 for External clock source 2 for the other clock.