Genius Dual Bus Configuration - Emerson PACSystems RX3i User Manual

User manual
GFK-2892G
Duplex Default State is employed whenever the output point data received in real time from
SBA#30 and SBA#31 disagree.
Note:
3.2.4

Genius Dual Bus Configuration

In Genius Dual Bus, two Bus Controllers are active on separate Genius busses. Both are
typically configured to use SBA#31. Each I/O device controls which bus it is connected to via
a Bus Switching Module (BSM). Thus, if the Bus Controller on the active bus ceases to
transmit, or the bus is physically broken, the I/O device controlling the BSM senses that
condition and switches to the alternate bus. The Genius devices connected in this fashion
must be configured for BSM Present.
accomplished using the Handheld Monitor. For VersaMax and 90-70 I/O Scanner Racks, this
is accomplished by configuring a target in the project folder.
Note that the Genius Bus Controller on the inactive bus will not be able to detect traffic from
the I/O devices. Following a bus switch, the newly active Bus Controller then needs to log in
all the I/O devices and begin servicing their I/O and alarms.
When GCG001 is used as the Bus Controller in this manner, application logic is required to
overcome the inherent delays resulting from Genius devices logging into the new bus
connections after a bus-switching event. The application must hold the last state of all
inputs (analog and discrete) until all devices have logged in and are broadcasting their input
data to the PLCs.
Each I/O device on the bus that does control a BSM needs to be configured as a BSM
Controller. Each such device will then be able to support the Switch BSM datagram (refer to
Section 6.4.9), which is typically used to test the behavior of the bus following a bus switch.
Devices configured as a BSM Controller will automatically switch away from a defective bus,
expecting that the alternate bus is intact and can function properly.
For Genius and Field Control devices, use the Genius Hand-Held Monitor (HHM) to set or
verify these parameters.
Figure 23:
1. To change the BSM Present configuration, press F2 (tgl).
2. To save the new selection, press F3 (entr).
3. Press F4 (next) to advance to the next configuration display.
Configuration
PNC Critical Network Ports feature does not cause a fatal fail-over in GCG-only PROFINET
systems because GCGs are Simplex devices. Users must monitor in logic both for a Loss of
all Critical Ports (either by monitoring the Controller port bits or watching for the Critical
Network Ports diagnostic message) and cause a logic-initiated roll-over, as well as watching
in logic for any GCGs to fail to then also cause a logic-initiated rollover.
For Genius blocks and Field Control this is
Chapter 3
Sep 2019
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