Configuring an ASCII Input
To configure an ASCII Input (ATC = ASCII Time Code):
- Navigate to INTERFACES > REFERENCES: ASCII Input 0 (or: INTERFACES > OPTION CARDS: ASCII Input 0). The status window will open, providing information on the current Reference ID, input Validity, ASCII Format, and if a pending Leap Second will be added to the UTC timescale at the end of the month. (See also Local Clock(s), DST.)
- Click Edit to open the configuration window:
The following settings are editable:
- Format Group: Determines the time code message format category (see also ASCII Time Code Data Formats.) Choices are:
- Format: Once a Format Group has been selected, one or more Format fields may appear, allowing you to select one or more time code Formats. For detailed specifications and limitations on the supported time code formats, see ASCII Time Code Data Formats.
Note: If Auto is chosen as the format group, the format will automatically be Auto-detect. VersaSync will attempt to identify the format of the incoming ASCII message.
- Offset: Provides the ability to account for ASCII input cable delays or other latencies in the ASCII input. The Offset value is entered and displayed in nanoseconds (ns). The available Offset range is –500 to +500 ms.
- Timescale: Used to select the time base for the incoming ASCII time code data. The entered Timescale is used by the system to convert the time in the incoming ASCII data stream to UTC time for use by the System Time. The available choices are:
- UTC: Coordinated Universal Time ("temps universel coordonné"), also referred to as ZULU time
- TAI: Temps Atomique International
- GPS: The raw GPS time as transmitted by the GNSS satellites (as of July, 2015, this is 17 seconds ahead of UTC time)
- A local clock set up through the Time Management Page: This option will appear under the name of the local clock you have set up. Refer to The Time Management Screen for more information on how to configure and read the System Time. Local timescale allows a Local Clock to apply a time offset for Time Zone and DST correction.
The incoming input time information may be provided as local time, but System Time may be configured as UTC time, so internal computations need to be performed. With the Timescale field set to “Local”, select the name of a previously created Local Clock. See for more information on Local Clocks.
Note: The Timescale of the ASCII input (as configured in the ASCII time source) must be set correctly, especially if other input references are enabled. Failure to configure the Timescale of the ASCII input correctly could result in time jumps occurring in the System Time when input reference changes occur. These time jumps could affect NTP and normal operation of the system.
- PPS Source: Choices are:
- Message: The 1PPS on time point is extracted from the ASCII message received.
- 1PPS Pin: The origin of the 1PPS on-time-point is the 1PPS input connector.
- Baud Rate: Determines the speed at which the input port will operate.
- Data Bits: Defines the number of Data Bits for the input output.
- Parity: Configures the parity checking of the input port.
- Stop Bits: Defines the number of Stop Bits for the input port.