Omron C-series - Manual (Page 22)

2-6 Section Link Adapter Repeater Input
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2-6 Link Adapter Repeater Input
Link Adapters AL002-(P)E and AL006-(P)E have repeater input terminals. They
are used when it is necessary to be sure that power has already been turned on
in a system connected to a branch line of the Link Adapter before signals are
transmitted along the main line. They should be kept connected (ON) when not
needed. When they are connected across, signals are relayed along the Link
Adapter’s main line. Once main line transmission has started, signals will contin-
ue to be relayed even if the repeater input terminals are opened (OFF).
Link Adapter
Master Branch system Terminator
Link Adapter
Relay input
Link Adapter
AL002-(P)E or
AL006-(P)E
Main line Main line
Branch
line
Units which may be connected to a branch line (as is branch system above)
Units with repeat input
terminals (I/O Link Units) Units without repeater input terminals
(Units other than I/O Link Units)
Connect the Link Adapter’s
repeat input to the I/O Link
Unit’s repeater output. Connect so that the repeater input sill be ON when
power is turned on in the Unit connected to the
branch line (in this case a Remote I/O Slave).
Branch
line
To the repeater input
Repeater output
Branch line
Power
source
Relay
X
X
If the repeater input is connected across directly (not used) in the above exam-
ple, control system operation will begin when the Master detects the terminator,
even if power to the branch system is off. In other words, the branch system is
ignored. The repeater input is used to prevent this from happening. When the
repeater input is connected as shown above, then the Link Adapter’s main line
will not transmit data as long as power is not turned on in the branch system,
thereby preventing the entire system from starting. Once the branch system is
operating normally, however, signals will continue to be transmitted along the
main line even if the repeater input turns OFF.