Input Reference Priorities
VersaSync can be synchronized to different time and frequency sources that are referred to as Input References, or just References.
References can be a GNSS receiver, or other sources delivered into your VersaSync unit via dedicated (mostly optional) inputs. It is also possible to enter a system time manually, which VersaSync then can synchronize to.
In order for VersaSync to declare synchronization, it needs both a valid 1PPS, and Time reference.
The concept of Reference Priority allows the ranking of multiple references for redundancy. This allows VersaSync to gracefully fall back upon a lower ranking 1PPS or Time reference without transitioning into Holdover, in case a reference becomes unavailable or invalid. The priority order you assign to your available references typically is a function of their accuracy and reliability.
Note: The References shown on your screen may look different from the illustration below, depending on your VersaSync Time and Frequency Synchronization System model and hardware configuration.
Each available type of Time and 1PPS input reference is assigned a human-readable name or “title” that is used in the Reference Priority table, indicating the type of reference. The reference titles are listed in the following table:
Reference priority titles
| Title | Reference |
|---|---|
| ASCII Timecode | ASCII serial timecode input |
| External 1PPS input | External 1PPS input |
| Frequency | External Frequency input |
| GNSS | GNSS input |
| PTP | PTP input |
| IRIG | IRIG timecode input |
| Local System | Built-in clock OR internal 1PPS generation |
| NTP | NTP input |
| User | Host (time is manually set by the user) |
| HAVEQUICK | HAVEQUICK input |
The number displayed indicates the number of feature inputs of that type presently installed in the VersaSync– starting with “0” representing the first feature input. For example:
- IRIG 0 = 1st IRIG input instance
- Frequency 1 = 2nd frequency input instance
- NTP 2 = 3rd NTP input instance
The columns of the Reference Priority table are defined as follows:
- Priority—Defines the order or priority for each index (row). The range is 1 to 16, with 1 being the highest priority and 16 being the lowest priority. The highest priority reference that is available and valid is the reference that is selected.
- Time—The reference selected to provide the necessary “Time” reference.
- 1PPS—The reference selected to provide the necessary “1PPS” reference.
- Enabled—The reference is enabled.
- Delete—Removes the Index (row) from the Reference Priority table.
