Communication Structure For Laboratory Testing - Hitachi 670 Series Application Manual

Section 5
Communication set-up
Internal
electronics
Direct
earth
(default)
For "soft earth"
remove jumper P4
R = 100 kohm
C = 100 nF
IEC08000073 V1 EN-US
Figure 77:
IEC10000207 V1 EN-US
Figure 78:
The strapping area/jumper P4 selects how internal signal earth and chassis earth are referenced
together. With a jumper between P4's terminals, signal earth and chassis earth are directly
connected. Without a jumper between P4's terminals, signal earth and chassis earth are connected
with a 100 kΩ resistor in parallel with a 100nF capacitor.
After jumper selection, reassembling is done in the reverse order to above. Do not forget to
reconnect protective earth cables.
5.5.7

Communication structure for laboratory testing

During laboratory testing, one transceiver 21-216 has to provide the timing. This is done by removing
the jumper on its S14 EXT CLK. Remember to restore the jumper after testing.
78
< 10 m between earth points
Outer shielding connected to
earth at both ends
Transc.
21-216
Make sure the boxes are
properly earthed with shortest
possible connections to, for
example, an earthed frame
Transceiver 21-216 and PCM should preferably use
the same auxiliary voltage supply (a 48 V battery)
Earthing principles
Earth selector jumper
© 2017 - 2023 Hitachi Energy. All rights reserved
1MRK505382-UEN Rev. K
Internal
electronics
PCM
directly earthed
Protective earth
screw (or any
screw with a good
earth connection)
IEC08000073-1-en.vsdx
P4
IEC10000207-1-en.vsdx
GUID-A1B07E54-B7A3-40E1-85A0-61AA17D03398 v1
Communication set-up, 670/650 series
Application Guide