Listec SCU 800-03, Руководство пользователя, Страница: 10 / 28

δ-LIST Manual SCU800-03 & SEC15
3.2.5 ALARM OUTPUT
An absolute fire alarm
FIRE! - AT
is set if the actual temperature (
T_act(n)
) of a measuring point
exceeds the maximum threshold. The LED ALARM A or ALARM B will be activated together with the
corresponding relay contact.
A differential fire alarm
FIRE! - DT
is set if the differential value (
T_dif(n)
) of a measuring point
exceeds the differential threshold. The LED ALARM A or ALARM B will be activated together with the
corresponding relay contact.
An alarm is only set if a warning was given during the previous measuring cycle and the temperature did
not fall below the warning threshold afterwards.
3.2.6 ALARM-SIGNALLING
Two alarm LEDs (6.1 DISPLAY) and two alarm relays (4.2.3.3 ALARM RELAYS) are dedicated to the
two sensor cable connections. An alarm in cable 1 will activate relay AL1 and LED A, respectively an
alarm in cable 2 will activate relay AL2 and LED B.
3.2.7 COMMUNICATION INTERFACES
The SCU 800 has one serial interface. It can be used as a RS-232 interface for programming or as a
protocol interface to other systems and is available as a 9-pin SUB-D connector (ST 4). (
 4.2.3.8
RS232 INTERFACE)
When using the SCU 800 as a slave in a master-slave system, either a RS485 or TTY current loop
interface can be used. The signals for these interfaces are on terminals COM+ and COM-. (
 4.2.3.5
COMMUNICATION)
Interface selection between RS232 and RS485 (TTY) takes place via a bridge in the connector ST4.
The interface type RS485 or TTY is determined by the component assembly (standard assembly is
RS485). (
 4.2.3.8 RS232 INTERFACE)
Further information on the serial ports and on protocols are to be found in the e xtended commissioning
manual for a δ-LIST system 60T024.
Page 10/28 LISTEC GmbH 60T023-01 / 24/01/08