GE Reason RT411, Техническое руководство

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Chapter 4 – Installation RT411
RT411 23
Figure 8: RT411 Grounding Strap
Electrical/Optical Time Input
The RT411 has one optical input and one electrical input for time reference. Both
accepts IRIG-B00X, PPX, DCF77, or any signal with frequency up to 5 MHz. The electrical
input support up to 5 Vdc signals.
Note the time accuracy of RT411 depends on the time reference source.
Figure 9: Electrical/Optical Time Input
To synchronize the RT411 using optical fiber, adequate optical fiber should be used,
respecting a minimum bend radius of 30 mm. To synchronize the equipment using the
electrical input, it is recommended the use of twisted pair.
For distances over 3 m, the use of an optical fiber cable is recommended to minimize
the effects related to EMC.
The length of the optical fiber cables should not exceed 2 km.
Selecting the Type of Time Input
An electrical jumper allows selecting the input to be used as time reference. The
electrical time reference port is enabled when making the connection in the INPUT
SELECTION connector, as shown below. In case the jumper is disconnected, the
equipment operates using the optical time reference port insulated.
Figure 10: Input Selection