TCG 01 User Manual
9
th
Edition: February 2007
Page 33 of 49
C.2
TCG 01 Command / Response Message structure
Units equipped with the Time-Tagging (event recording) option provide four
command/response message pairs that specifically support Time Tag management and
retrieval.
All command and response messages used by TCG 01 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>)
C.3
TCG 01 Commands related to Event Time Tagging
These commands and their responses contain ASCII characters only. A tool such as telnet
provides a convenient way to explore the Time-Tagging command/retrieval functions
manually. Note that the TCG01 native serial protocol does
not
include station
addressing. In a network-connected system, the address of the Serial to Ethernet
interface device can serve as the station address. Tekron International can supply such
devices if required.
P
Ps command: Get Status
The Ps command invokes a
Ps
response that contains the clock status – which includes
the number of tags currently in the time-tag event buffer.
Command (7 bytes [0-6]):
Transmitted format:
@@Ps#
<
CR
><
LF
>
Response: (33 bytes [0-32]): Received format:
@@Ps
{
26 data bytes
}{
cs
}<
CR
><
LF>
Byte # Description (Data bytes only, bytes 4-29 in received message)
4
Antenna feed fault –[A] only if antenna line is short or open circuit *
5
No GPS Solutions – [T] only if no satellites are available for time calculations *
6
S/N level low – [S] only if S/N level is abnormally low for more than an hour *
7
Oscillator Error High – [X] only if Oscillator Control value is extreme *
8
Oscillator DAC out of range – [H] or [L] only if Oscillator Control tending
towards extreme *
9
GPS Fail – [B] only if internal GPS receiver sub-system not operating properly *
10
Not implemented – ASCII [space] always
11
Tracking Satellites – [0-9] = # of satellites in time solution (see note 1 below)
