C.12 Option 28: Power System Time, Frequency and Phase Monitor 123
hh:mm:ssU = Time of Day, UTC
(or)
hh:mm:ssL = Time of Day, Local
ss = Status
first character is Reference Status:
0 : Locked;
1 : Unlocked;
second character is clock status per IEEE P1344
+f.fff signed Frequency Error in Hz.
+t.tttt signed Time Deviation in seconds.
ppp.pp Phase Angle, 0 to 360 degrees.
vvv.vv Line voltage, rms Volts.
Start Broadcast Mode–True Time
Command: BT, OT
BT configures the Standard RS-232 broadcast mode to send Time, Time Quality and Frequency,
once per second, in True Time format. OT configures the Option RS-232 broadcast mode to send
Time, Time Quality and Frequency, once per second, in True Time format.
Response: broadcast mode, UTC:
<SOH>DDD:HH:MM:SSQTsDS.thmFsU.thm
C
Where:
<SOH> = ASCII start of header character (01h)
DDD = Day
: = ASCII colon (3Ah)
HH = Two digits of the hour of day
MM = Two digits of the minute of day
SS = Two digits of the second of day
Q = Quality Sentry character ( , “.”, “*”, “#”, “?”)
space (20h) error 5 1 µs
. period (2Eh) 1 5 error < 10 µs
* asterisk (2Ah) 10 5 error < 100 µs
# pound sign (23h) 100 5 error < 1000 µs
? question mark (3Fh) error = 1000 µs
T ASCII T, indicates start of Time Deviation Field
s Sign character + (2Bh) or - (2Dh)
D Tens of seconds (Time Deviation
. Period, decimal point
thm Tenths, hundredths and thousandths of seconds
F ASCII F, indicates the start of Frequency Deviation Field
s Sign character + (2Bh) frequency above nominal or
- (2Dh) frequency below nominal
U Units of Hertz (Frequency Deviation)