Bus Extender Unit Module IOP371
Metso Automation MAX Controls Inc.
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277596
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11-7
On power-up transceiver 1 is selected. If a failure is detected, the circuit will
switch the link to transceiver 2, a digital output will be set and an LED will
identify which link is operational. If the link cannot be established using
transceiver 2 the circuit will go back to transceiver 1 and the sequence will
repeat indefinitely until the link is established.
Power on reset – The power on reset circuit includes a watchdog timer to
monitor the operation of the CPLD.
Optical Cabling
The two front-accessible optical transceivers, designated Link 1 (top link)
and Link 2 (bottom link), each have two ST type connectors, one to transmit
(Tx) and the other to receive (Rx). The fiber optic cable connects the
transmit output of one BEM to the receive input of the other BEM.
Multimode 62.5-micron cable is used to connect the local and remote
Extender modules. Cable is run between the redundant optical transceivers
to support redundant optical cable pairs. If redundant cables are provided,
one cable pair is always active while the second pair serves as a hot standby
link. See "Ensuring Link Availability.
Model 564 and maxPAC I/O Compatibility
Because the Extender module has the same form factor as the Model IOP I/O
modules, it can be used in either Model 564 or maxPAC applications. The
module installs in an IOP015 4-pack I/O Chassis or any of the maxPAC
chassis described in chapter 1.
Termination Requirements
In an I/O configuration using BEMs, an additional terminator is required at
the remote BEM I/O bus location. This is in addition to the terminator
assembly usually installed at the end of the I/O bus. For model 564 I/O
installations, use CP0102 terminator assembly. For maxPAC applications,
use CP0402 terminator assembly.
Redundant Configuration Approaches
In a redundant configuration, I/O may be configured only at the remote end
or both locally and remotely. A redundant configuration consists of a
primary and secondary DPU, each with its own associated BEM.
Four Configuration Approaches
Redundant DPUs and redundant BEMs may be employed in any of the
following configuration schemes: