Hitachi 670 Series Application Guide

Type of LDCM Short range (SR) Short range (SR) Medium range (MR) Long range (LR)
Total attenuation 9.95 dB 13.05 dB 28.04 dB 28.56 dB
Optical link budget 11.8 dB 18.8 dB 28.8 dB
30.8 dB
1)
28.7 dB
Link margin 1.85 dB 5.75 dB 0.76 dB
2.76 dB
1)
0.14 dB
1) Applicable for revision r11 and later.
5.4 Galvanic X.21 line data communication (X.21-LDCM)
GUID-75B89AAC-1A2D-4774-B357-88F7AB7F392A v1
5.4.1 Introduction
GUID-D02150FC-54F5-4CE4-8D3D-9F8796B6A527 v3
The galvanic X.21 line data communication module is used for connection to telecommunication
equipment, for example leased telephone lines. The module supports 64 kbit/s data communication
between IEDs.
Examples of applications:
• Line differential protection
• Binary signal transfer
5.4.2 Design
GUID-0570749A-516C-47D6-A818-83416759BA90 v7
The galvanic X.21 line data communication module uses a Hitachi Energy specific PC*MIP Type II
format.
C
IEC07000196 -2-en.vsdx
IEC07000196 V2 EN-US
Figure 65: Overview of the X.21 LDCM module
Section 5 1MRK505382-UEN Rev. K
Communication set-up
68 Communication set-up, 670/650 series
Application Guide
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Hitachi 670 Series Specifications

General

Brand	Hitachi
Model	670 Series
Category	Control Unit
Language	English