TrueTime 151-602 - 3-116.1 SERIAL PORT EMULATION COMMANDS; 3-116.2 MODE C - CONTINUOUS TIME, ONCE PER SECOND

X
X
L
L
D
D
C
C
M
M
A
A
N
N
.
.
d
d
o
o
c
c
3
3
-
-
1
1
7
7
R
R
E
E
V
V
E
E
3-116.1 SERIAL PORT EMULATION COMMANDS
As a convenience to our customers, the TrueTime XL-DC emulates most of the Serial Port commands
of the older GPS-DC Mark II GPS Synchronized Clock. Most customer programs written to interface
with the Mark II Serial Port will also interface with the XL-DC Serial Port if the emulation mode is
enabled with Keypad Function 16. Refer to the following table for the available emulation mode
commands.
EMULATION MODE COMMANDS:
COMMAND MODE DESCRIPTION
C Mode C Continuous time, once per second
F Mode F Format Time Message
R Mode R Reset to default time format and Mode C
T Mode T Time on request
When the emulation mode is enabled with Keypad Function 16, the Serial output defaults to Mode C. If
the unit was in the emulation mode at power-down, it will power-up in the emulation mode and default
to Mode C.
3-116.2 MODE C - CONTINUOUS TIME, ONCE PER SECOND
Use Mode C to set the Serial Port to output the time message once each second. Mode C is the power-
up default. To request Mode C, send the ASCII character C to the Serial Port. The format of the output
string may be changed with Mode F. The default output string format is:
<SOH>DDD:HH:MM:SSQ<CR><LF>
where:
<SOH> = ASCII start-of-header character (Hex 01)
DDD = 3-digit day of year
: = ASCII colon character
HH = two-digit hours
MM = two-digit minutes
SS = two-digit seconds
. = ASCII period character
mmm = three characters for milliseconds
Q = time quality character (see following)
<CR> = ASCII carriage return character
<LF> = ASCII line feed character
The time quality character may be one of the following:
SPACE which indicates a worst-case error less than threshold 1
. which indicates a worst-case error greater than or equal to threshold 1
* which indicates a worst-case error greater than or equal to threshold 2
# which indicates a worst-case error greater than or equal to threshold 3
? which indicates a worst-case error greater than or equal to threshold 4