CTI Janus Programmable Automation Controller IOG
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7.1.4
Dual RBC Support
The Janus controller supports dual Remote Base Controller (RBC) configurations using an RS-485 network. Coaxial
dual media cabling is not supported.
A dual RBC configuration consists of two remote base controllers installed in a special base (CTI 2500-R11-A or
Siemens 505-6511). These bases also support the installation of dual power supplies, providing redundant sources
of power.
The dual RBC configuration provides redundant control of the I/O base. When power is applied to the base (and
two RBCs are installed and operational), the RBC in the rightmost controller slot assumes the role of the active
RBC, reading and writing the base I/O. The other RBC assumes the standby role, responding to status requests
from the 2500 Series controller, but not accessing the base I/O.
When a dual RBC configuration is detected, the Janus controller continuously monitors the status of the status of
both RBCs. If a problem is detected with the standby RBC, the 2500 Series controller will disable it. Should the
controller detect a problem with the active RBC while the standby RBC is operational, it will direct the standby RBC
to assume the role of active RBC and disable the previously active RBC.
The standby RBC, if operational, also monitors the condition of the active RBC. If the standby RBC detects a
problem with the active RBC it will automatically assume the role of the active RBC and will disable the previously
active RBC. RBC status is reported to the Remote I/O fieldbus driver.
An RBC that has been disabled can be re-enabled by temporarily changing the address switch to a different address
then changing it back to the original address. Alternately, the RBC can be re-enabled by cycling power to the base.
Using
Janus Workbench
, you can manually direct the RBCs to swap roles (if the standby RBC is operational). This
capability is especially useful when executing diagnostic routines on an RBC, since diagnostic routines are always
run on the standby RBC in dual RBC configurations.
RS-485 cabling to the dual remote base controllers must comply with the cabling and topology standards described
in
See
Other Topology Considerations
within this section for typical dual RBC connections.
NOTE
You can use a CTI 2500-RIO-A (firmware version 7.03 or higher, CTI 2500-RIO-B,
or Siemens 505-6851-B remote base controller in a dual RBC configuration.
However, you cannot intermix CTI and Siemens RBCs in the same base.
7.1.5
Configuring Local and Remote I/O
Local and Remote I/O can be configured using
Janus Workbench
. See the Workbench help system for compete
information regarding configuration and I/O support.
