Alstom Reason RPV311, Technical Manual

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RPV311 Chapter 15
– Installation
RPV311-TM-EN-6 290
The equipment indicates sync when the data acquisition frequency is according to the equipment's nominal
acquisition frequency and the equipment's internal clock is updated.
The RPV311 internal clock is updated with every hour rollover or when the equipment turns to sync mode.
If the IRIG-B signal is not valid or not connected, the device indicates no sync. If the IRIG-B signal is
connected and valid, the time quality of the time reference reported in the IRIG-B frame is shown by the
RPV311, but the time quality is not considered by the synchronization.
In the absence of the IRIG-B signal, the equipment can be synchronized by an SNTP time server, however,
the acquisition frequency does not have the same stability afforded by the IRIG-B signal (accuracy less than
12 ppm), and the equipment does not indicate sync.
The IRIG-B signal is preferred over the SNTP time server.
If no IRIG-B signal is available and the SNTP server is unreachable, the unit obtains the time of an internal
CMOS clock. Drift is better than 0.1 second in 24 hours.
The RPV311 has an electrical and an optical IRIG-B input, as shown in Figure 131 .
Figure 131: Electrical and optical inputs for sync using IRIG-B
To synchronize the equipment using fiber-optic input, use the appropriate fiber-optic type, considering its
minimum curvature radius.
The use of a twisted pair cable is recommended for the electrical input.
For distances greater than 3 m, to minimize EMC effects, the use of fiber-optic cable is recommended.
5.14.1 CONNECTION DIAGRAM OF THE SYNCHRONISM INPUTS
Figure 132: Connection diagram of electrical synchronism inputs
For information about electrical synchronism input specifications, see Section 2.4 of the Specifications
Chapter 17.