TEK-TCG 01-G-Manual-v6-052021
P a g e
| 48
www.tekron.com
© 2021 by Tekron International Limited. All Rights Reserved. All trademarks are the property of their respective holders. The
information in this document is provided for informational use only and is subject to change. For further information or support,
go to www.tekron.com.
Event Recording Specification
Tag Data
Time tags use UTC time, and each tag includes the year, day of year, hour, minute and second,
as well as fraction of second to a resolution and accuracy of 100 ns. The TCG 01-G measures
time internally in 40 ns intervals, rounding to the nearest 100 ns for time tag storage purposes,
thus allowing accuracy to equate to resolution. Each tag record includes the input channel
number, as well as the clock sync status at the tag time.
Tag Storage
The TCG 01-G stores time tags in a data queue designed as a circular buffer. The maximum
number of time tags that may be stored is 512. If further events occur when the buffer is full,
the TCG 01-G sets an overflow status and continues storing tags, overwriting the oldest data
first.
Tag Retrieval
The user can retrieve time tags from the buffer using a request/response protocol operating
over the TCG 01-G’s P4 serial port interface. Tags are retrieved from the buffer - oldest data
first.
The TCG 01-G can be configured to broadcast either status or serial time strings over the serial
port. Most users of the time tag option will want to suppress all broadcast outputs to simplify
the task of time tag data collection. However, if output strings
are
selected, the TCG 01-G will
still output time tag information when requested, timing the responses to avoid interference
with the other traffic on the port.
TCG 01-G Command / Response Message structure
Units equipped with the event recording option provide four command/response message pairs
that specifically support time tag management and retrieval.
All command and response messages used by the TCG 01-G have the same structure:
Prefix:
2 bytes (ASCII “@” characters)
Type:
2 bytes (ASCII alphabetic characters - case matters!)
Data:
n
*
bytes (May be ASCII or binary data)
* The length of the “Data” field is determined by “Type”. Command and Response commands,
while sharing the same “Type” field, have different data content and length.
Checksum:
1 byte, binary XOR over all bytes in the “Type” and “Data” fields
Suffix:
2 bytes (ASCII <CR><LF>)
