ABB ETL600, Instruction Manual

Page: 119 / 382

ETL600 1KHW001489-EN
ABB Switzerland Ltd
3.6.8.19. Interference in Speech Band
The NSD600 is under normal operating conditions secure against:
•
Speech
•
Sweep tones in speech band
•
Test tones of the PLC equipment (generated via HMI600)
•
DTMF signaling (according to CCITT-48430 or ITU-T Q.23)
•
MFC signaling (
for direct tripping commands only
)
Under certain circumstances an NSD600 alarm may arise, e.g. when a
discrete frequency of a tone generator meets a trip frequency, but no
unwanted command will be activated.
3.6.8.20. Compatibility with Inband Modem Signals
Generally speaking, modem signals have to be avoided in the trip
frequency band (0.3 … 2.0 kHz). They should be allocated above
speech or in other channels of the ETL600.
Caution
NSK600 modems are also not allowed in the
NSD600 trip frequency band (neither FSK- nor
DAPSK modems).
3.6.8.21. 3 APLC in 8 kHz Operating Mode with NSD600
The whole functionality of one NSD600 without restrictions is provided
in the first 3.2 kHz channel of the “3 APLC in 8 kHz” operating mode.
The operating principle is the same as in 4 kHz operating mode, i.e.
the transmission of the trip frequencies takes place in the band 0.3 …
2.0 kHz, but there is only one own guard signal at 2240 Hz for the
NSD600 available.
3.7. Event Recorder
3.7.1. General
The event recorder integrated in the HMI600 program (refer to
chapter 4
) registers special events of the ETL600 system, provides
them with an accurate time stamp and stores the information
sequentially into a non volatile memory.
The resolution of the events which can be discriminated between is
1 ms.
There are two different kind of events (they are recorded into two
different blocks of the memory):
•
the NSD600
command
events
•
the ETL600 and NSD600
alarm, warning & manipulation
events
Structure and Function November 2005 3-87