Spectracom NetClock 9489 - Page 373

The choice of format group determines t he format choices available in the Format
1, Format 2 and Format 3 fields.
Format 1: Selects either the first of up to three, or the only format message
to be output. See "ASCIITime Code Data Formats" on page387 for a
description of available formats.
Format 2: Selects the second consecutive format message to be outputted.
Select “None” if only one output format is desired. See "ASCIITime Code
Data Formats" on page387 for a description of available formats.
Format 3: Selects the third consecutive format message to be outputted.
Select “None” if only one output format is desired. See "ASCIITime Code
Data Formats" on page387 for a description of available formats.
Signature Control: Used to control when the IRIG modulation will be present. This func
tion allows the modulation to stop under certain conditions;see also "Signature Control"
on page141.
Output Mode: This field determines when the output data will be provided. The avail
able Mode selections are as follows:
Broadcast: The format messages are automatically sent out on authorized con
dition (Signature control), every second a message is generated in sync with the
1PPS.
Request (On-time): A format message is generated in sync with 1PPS after the con
figured request character has been received.
Request (Immediate): A format message is generated as soon as the request char
acter is received. As this selection does not correlate the output data to the on-time
point for the message, in Data Formats that do not provide sub-second inform
ation (such as Formats 0 and 1 whereas Format 2 provides sub-second inform
ation), it should be noted that the output data can be provided immediately, but a
time error could occur when using the on-time point of the message in addition to
the data for timing applications.
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)
NetClock User Reference Guide 357
APPENDIX