OSN3500 external clock source: there are two channels, 0xf001 and 0f002.

2M External Clock Derived Priority Table: used to output clock externally through the external clock port, the configuration method is similar to the system priority table, but slightly different.

1、 External Clock Input and Output Mode

Input and output are divided into BIT mode and HZ mode.

BIT mode: mainly handled by the clock chip (SA586, etc.), supports S1 byte extraction and setting;

HZ mode: mainly handled by logic, does not support SSM protocol.

2、 External clock impedance

There are two types of impedance: 75 ohm and 120 ohm.

3、 External clock status detection:

a) BIT mode: clock chip detection. LOSLOFAIS can be detected.

b) HZ mode: logic detection.

Impedance setting:

If the clock source state of the 75 ohm input impedance is present, the 75 ohm input impedance is set to logic go;

If it is not present, the 120-ohm state is detected as present, and if the clock source state of the 120-ohm input impedance is present, the 120-ohm input impedance is set to logic go;

If the clock source state of the 120-ohm input impedance is also not present, the default is to set the 75-ohm input impedance to logic go.

4、 Clock source failure condition:

Same as business source, failure condition can be set.LOS is the default failure condition, LOFAIS can be set as failure condition or not by command.

5、 External Clock Connection

75 ohm cable connection, 120 ohm cable connection, one cable can support up to 2 channels of external clock signal transmission at the same time.

OSN1500/2500/3500/7500: AUX, EOW or PIU on.

OSN7500II: on cross board.

The related technical information and SDH equipment troubleshooting procedures in this chapter are collected and organized by Shenzhen Optical Transmission Network Technology Co.( www.opticaltrans.com), please retain! Our company specializes in Huawei SDH optical transmission equipment, SDH transmission equipment sales.