11
Event register
for the serial
communication
The annunciator unit incorporates a separate
event register which contains information on the
type of event and the channel number including
a synchronous time stamp. This enables a higher
level system to read out events from the annun-
ciator 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 syn-
chronized, 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 register,
the corresponding bit in the matrix register is
activated.
Fig. 9. Event registration in SPACOM systems.
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
