14
Event register for the
serial communication
The annunciator unit incorporates an event reg-
ister which contains information on the type of
event and the channel number including a syn-
chronous time stamp. This enables a higher level
system to read out events from the annunciator
over the SPA bus serial communication. The
event register holds 50 events. The time stamps
are relative and the time span is max. 60 s. The
clocks of the interconnected units are synchro-
nized, generally once per second, by the higher
level system (the SPA bus master). The time
resolution between the channels is 5 ms.
The annunciator unit also includes a channel
matrix register which operates in parallel with
the event register and in which each channel
corresponds to one bit. If a channel is activated
during an overflow situation of the even regis-
ter, the corresponding bit in the matrix register
is activated.
Overflow
Overflow
Time
Slave
Channel
Code
2
1
500
Adding of
users text
Event register
Clock
SPA-bus
Synchronization
SRIO
Printer
Host system
Time
Slave
Channel Code
Channel Code
Time
Events
Clock
0 - 60 s
SACO alarm module
Event
register
Overflow
1
2
3
4
5
6
7
8
9
10
11
14
16
Event overflow
matrix register
SPA-bus
Clock
0 - 60 s
Time
1
2
3
.
.
.
.
n
Channel Code
Events
SPA-bus
SPACOM protective relay module
Event
register
12
13
15
Time marking: year, month,
day, hour and minute
1
2
3
.
.
.
.
.
.
.
48
49
50
Fig. 11. Event registration in SPACOM systems.