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5.2
Start-up
The procedure for starting up a link system is explained below.
1. Although there are no restrictions on the order in which the power supply to each station must be switched
on when starting up a link system, link operations will not commence until the power has been switched on to
station No.0 (the master station.) Create the program used for controlling and computing the link data after
the master station's participation flag has been set at ON.
2. In order to check for duplications in the setup station No.s when starting up a link system for the first time,
switch on the power supply to all stations other than No.0 first of all, and then switch on the power to station
No.0 lastly. An error will be displayed for the duplicated station.
Link operations will not be carried out if a duplication occurs in the station No.s. Eradicate the duplicated
station No., and then switch on the power to the link module base.
Note #1: There are cases where the following operations are performed when the power is switched on during
link system startup if duplicated station No.s exist. Eradicate the duplicated station No., and then
switch the power on again.
a ) When station No. 0 (master station) is duplicated
• None of the link modules will execute link operations.
• Only one of the duplicated stations will perform normal operations, and the ERR LED will blink
at intervals of 0.5 seconds with the other station (link operations will not be performed.)
b ) When a station other than station No. 0 (master station) is duplicated
• The ERR LED in the stations for which the duplication exists will blink at intervals of 0.5
seconds.
• Only one of the duplicated stations will perform normal operations, and the ERR LED will blink
at intervals of 0.5 seconds with the other station (link operations will not be performed.)
Note #2: There are cases where operating stations will detect a transmission route cut-off error if the power to
multiple stations is switched off or cut off simultaneously, but this will be automatically restored and
link operations resumed. Create a program to monitor the link participation flags and prevent the link
data from being used during the period that participation flags are set at OFF.
5.3
Participating in and leaving link systems
If the number of the station connected to a link system and the link assignment settings are correct, it is
possible for a link module to participate and leave the link during link operations.
Although participating in and leaving link systems is possible regardless of the master/slave station
relationship, if the master station leaves the link using the wrong procedure, the station will effectively
disappear and link operations will be terminated.
The procedures for leaving and joining the ling during link operations, and the precautions that must be
observed are listed below.
1 ) If the power supply to station No.0 (master station) is switched off after link operations have started, the
master station transition process will be performed, and link operations will resume when this has been
completed.
The No.0 master station authority will then be moved across to the next station with the smallest station No.
(temporary master station in this event, and this will be repeated, with the next smallest station becoming
station No.0 (temporary master station) whenever the power to the master station at that time is switched off.
However, if the power supplies to the master station and the station with the next smallest station No.
(temporary master station) are switched off simultaneously during operations, link operations will be
terminated. In order to prevent the termination of link operations, it is therefore necessary to ensure that each
station is switched off one by one when leaving the link system.
2 ) If station No.0 (master station) leaves the link by having its power switched off and then rejoins the link
again, it will become a slave station (the temporary master station at that time will remain as the master
station.) However, if the power to the temporary master station is switched off, station No.0 will become the
master station as it has the smallest station No. of all slave stations.
Chapter 5. Installation and start-up
5-4
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