Dual Line System; Online Operation - Toshiba V Series User Manual

Chapter 6 System Operation

6.2 Dual Line System

6.2.1

Online operation

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Use of a dual-line S controller (SPU65) permits dual-line station configuration. No
applications can be executed while the S3 dual-line system is in standby status, however,
the standby set is unable to make inring requests or register scan transmission, etc.
A redundant system must have information on the transmission status of the other set, so
the standby set must be engaged in ADMAP transmission to permit the online set to
monitor the status of the standby set. This can be done by setting the AO switch in Table
3-2 to the ON position.
The next and subsequent sections describe the operation of applications, etc. at initial
start or when standby operation is upgraded to online operation or when online operation
is downgraded to standby operation.
(1) Initializing
When initial start sets the system in online operation, application operation concerning
the AN712 module is the same as the initializing operation shown in figure 6-2. However,
it is not necessary to issue inring requests or online requests because the AO switch is
set to the ON position.
(2) Downgrading to standby
The station status shown in figure 5-6 is monitored during online operation. When STATE
in this information becomes DOWN (1 in bit 10), it indicates that the AN712 module has
failed due to an unremediable error.
Take the following steps to made a changeover in the dual-line system.
Dual-line system changeover procedure (AN712 module down)
1) Record and notify the error using the S3 application
2) Change the S3 dual-line system from one set to the other.
The online set (local station) shown on the live list of figure 5-7 is monitored for status.
When it is 5 seconds or more after the local station is disengaged from the token ring
(IR=0), an error with both buses (LAF=LBF=1) or no carrier signal (NCA=NCB=0), if
continued for 5 seconds or more, is judged as an error with both ADMAP transmission
lines.
Take the following steps to made a changeover in the dual-line system.
Dual-line system changeover procedure (Error with both transmission lines)
1) Record and notify the error using the S3 application
2) Issue requests to stop scan transmission (at all speeds: high, medium, and low) to
the AN712 module.
3) Change the S3 dual-line system from one set to the other.
(3) Standby set transmission line diagnosis
The status of the online set (local station) and that of the standby set (opposite station)
on the live list of figure 5-6 are monitored during online operation.
If the local station is engaged in the token ring (IR=1) and the opposite station
disengaged from the token ring (IR=0) for 5 seconds or more, take it as a standby
ADMAP transmission error, and record and notify it using the S3 application.
model 3000 ADMAP-5M AN712 Module User's Manual