SA-ACU-SR User
Manual
S-Access GmbH
Tel: +41 44 700 31 11
Oberhausenstrasse 47
Page
10
of
16
Fax: +41 44 700 31 03
8907 Wettswil a/A
Email:
Switzerland WEB:
www.s-access.ch
Under normal power conditions, the device (itself) controls the alarm/signal outputs of the
relay. In case of a power failure on the device, both “urgent” and “non-urgent” alarms will be
activated.
Alarm conditions
Urgent alarm:
•
at least one of the devices displays urgent alarm;
•
power failure of any of the devices;
•
power failure of the aux5V
dc
supply in the SA-R shelf;
•
Power failure of one of the –48V
dc
supplies.
Non-urgent alarm:
•
at least one of the devices displays non-urgent alarm;
•
power failure of any of the devices;
•
power failure of the aux5V
dc
supply in the SA-R shelf;
•
power failure of one of the –48V
dc
supplies.
Note:
The devices of the universal AccessGain platform can have “alarm cut off”
commands. If alarm cut off is activated, the alarm relays are disabled.
3.5 Connection of the shelf to the clock source
The universal AccessGain platform has a possibility of synchronization of signals transmitted
from the external clock source. The SA-ACU-SR module contains a unit designed to receive
and process (supervise) clock impulses at a frequency of 2048 kHz. The socket for the
connection of the external clock source is of a 75-Ohm BNC type.
The incoming clock impulses are converted up to the TTL level and transmitted through the
rear panel to the central clock oscillator of each device.
The clock input accepts a 2048 kHz signal with a peak voltage range from 375 mV
p-p
to 3 V
p-
p
. This allows to establish a connection between transmit and receive clocks according to
ITU-T Recommendation G.703.10.
3.6 Connection of external devices over the RS485 interface
The RS485 interface is used to connect devices installed into shelves or external devices to
the SA-ACU-SR module installed in one of the shelves.
Note:
The bus of the RS485 interface requires the 120 Ohm terminal resistance,
therefore, a terminator must be installed on the data terminal devices connected in
circuits. The terminator on the SA-ACU-SR module is set by J6, J7 jumpers.
