Chapter 4 Loop Back Check - Hitachi H Series Instruction Manual

For preventing termination of linking operation at the time of power OFF of the link
system, therefore, turn OFF the power for a station at a time.
(4) If overlap of station numbers is present, the following operation may occur
depending on the timing of power ON at the time of activation of the link system.
Eliminate overlap of station numbers and then turn ON the power once again.
(a) Case where station No.0 (master station) is overlapped
- No indication is made by 7-segment displays of all link modules.
- One station only normally operates among overlapped stations, and E6 (or
rarely E3) is indicated on other overlapped stations.
(b) Case where a station number other than 0 (master station) is overlapped
- E6 (or rarely E3) is indicated on all the overlapped stations.
- One station only normally operates among overlapped stations, and E6 (or
rarely E3) is indicated on other overlapped stations.
(5) At the time of activation of the optical link system that contains a station whose
power source on the basic base is OFF, connect 5 V DC power supply to external 5
V DC input table of the station before switching on other stations.
- 7-segment displays of overlapped stations only indicate "000". Nothing is
indicated on other stations, and linking operation is not commenced.
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