GE RPV311, Technical Manual

Page: 239 / 295

Chapter 15
– Installation
RPV311
RPV311-TM-EN-7 239
For information about digital input specifications, see Chapter 17: Technical
Specifications.
17.1.1
Connection diagram of the digital inputs
Figure 131: Connection Diagram of Digital Inputs
18 Time Synchronization Inputs
Timing synchronism is provided by the IRIG-B000/001/002/003/004/005/006/007
signal. The IRIG-B signal is used to keep the RPV311 data acquisition frequency
constant and to provide the time stamp for the equipment.
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 132 .
Figure 132: Electrical and optical inputs for sync using IRIG-B