6 F 3 B 0 3 5 6

5. RAS function

5.1Behavior in trouble

(1)Optical fiber system

Station down

If a station (either main, back-up or general) becomes down, the abnormal station will be disconnected from the S20LP system (re-configuration), then communications of remaining stations will be re-started. If two station (either main, back-up or general terminals) become power off, the S20LP system will split into two independent S20LP systems at the power off stations.

S20LP loop No.1

Power off

S20LP

STN #1

OTR2 OTR1

OTR1 OTR2

S20LP

STN #6

Power off

OTR1 OTR2

OTR2 OTR1

OTR1 OTR2

OTR2 OTR1

S20LP STN #2

S20LP STN #5

OTR1 OTR2

OTR2 OTR1

OTR1 OTR2

OTR2 OTR1

S20LP

STN #3

OTR2 OTR1

OTR1 OTR2

S20LP

STN #4

S20LP loop No.2

Transmission cable breakage

If both transmitter and receiver lines are broken (*1) or if one of the two lines is broken (*2), the S20LP system will cut off the broken lines.

OTR2

To S20LP STN #n

OTR1

S20LP STN #m

Broken lines

OTR1 OTR2

OTR2

OTR1

(*1)

(*2)

S20LP STN #l

OTR1

To S20LP STN #o

OTR2

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Toshiba S20LP instruction manual RAS function, Behavior in trouble, ∙ Station down, ∙ Transmission cable breakage