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I.L. 40-201.9
4.5
Communication Channel Type (COMM)
For ON-OFF Power Line Carrier select COMM = 2.
For FSK PLC set COMM =3.
Figure 3-6 shows that COMM = 3 allows phase comparison of both positive and negative half-
cycles.
With setting COMM = 2 the phase comparison on negative half-cycle only is performed.
4.6
Local Delay Time (LDT1 and LDT2)
These settings delay local values LP and LN (see figure 3-6) to compensate for the propagation
delays associated with received signals MARK (M) and SPACE (S).
These settings are to be determined by the measurement described in chapter 4 – 4.4.4.
(page 4-8)
Please note that for 2-terminal applications only LDT1 is used. For 3-terminal line both LDT1
and LDT2 must be measured and entered as settings.
4.7
Transmit Keying Level (IKEY)
As explained in 3.2.2 and illustrated in figure 3-3, the IKEY defines the threshold generating the
squarewave to be sent to the remote terminal. Please be aware that the IT waveform from
which this transmitted signal is generated is the function of coefficients described in section 4.3
above.
For the coefficients:
C0 = 0.7
C1 = 0.1
C2 = 0.2
The IKEY = 0.3 is recommended.
The IKEY setting is the instantaneous value of "IT".
4.8
Local Positive Level (LP)
This setting determines the local squarewave generation as shown in section 3 - 2.1 and figure
3-3.
Notice that the local negative level LN is internally computed from LN = - LP.
the recommended LP setting should be the same as IKEY setting.
4.9
Reclose Block Enable (RBEN)
The following settings are provided for system flexibility:
4.10
Unblock Logic Enable (UNBK)
This setting is primarily for Power Line Carrier (PLC) applications.
5-4
• NORB
— No Reclose Block for the system. This logic may be provided by exter-
nal devices.
• ALRB
— Reclose block will be activated for all types of faults.
Power Automation and Protection Division
REL 352 Version 1.00
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