ALTUS Nexto NX3004 User Manual

6. Redundancy with NX3030 CPU
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Stand-By State
In this state the CPU is ready to be switched to the Active state, in case there’s a request for that, as a
failure in the Active CPU.
The Stand-by CPU also verifies its own diagnostics and can be switched to the Not-Configured or
Inactive state, in case some failures occur.
PROFIBUS masters are enabled in the passive state. The passive mode is used to test the
transmission and reception PROFIBUS circuits and the physical layer, to avoid an occult failure to
happen. Total failure in PROFIBUS networks configured as vitals cause a switching to the Inactive
state. A total failure in a PROFIBUS network damages both composing networks (redundant
PROFIBUS network) and the single composing network (non-redundant PROFIBUS network).
If the Ethernet interfaces are enabled with vital failure option, clients are enabled in passive state.
Total failures in Ethernet networks configured as vital cause a switch to the Inactive status. A total
failure in an Ethernet network reaches the two networks that comprise (enabled Communication
Redundancy option) or the only network that compose (Redundancy option disabled
Communication).
Inactive State
This state is normally reached after some failure types, or due to a manual request before a
programmed maintenance.
PROFIBUS masters are enabled in the passive state. The passive mode is used to test the
transmission and reception PROFIBUS circuits and the physical layer, to avoid an occult failure to
happen.
Before switching to another state, first the diagnosed failures must be corrected or the programmed
maintenance executed, if those have driven the CPU to Inactive state. After, a transition for the Not-
Configured state must be done, requesting a configuration. Then, a switch to the Starting state must
be executed. After the Starting state, the CPU can:
 Return to the Inactive state, if determine failure types remain
 Return to the Not-Configured state, in case of other failure types
 Go to Stand-by state, if the other CPU is in Active state
 Go to Active state, if the other CPU isn’t in Active state
PX2612 Redundancy Command Panel Functions
The PX2612 redundancy command panel is shown on Figure 6-4, while Figure 6-5 shows its frontal
view with more details. Besides this, Figure 6-6 shows how this panel must be connected to the
PLCA and PLCB half-clusters.
The PX2612 is divided in two sections: one controlled by PLCA and another by PLCB. These
controllers are possible through cables AL-2317/A for PLCA and AL-2317/B for PLCB, and allow
each CPU to read three buttons, write on three LEDs and a NO relay contact.
Observing the frontal view on Figure 6-5:
 PLCA executes the STAND-BY and INACTIVE buttons reading in PLC A sector.
 PLCA executes the TURN ON PLC B button reading.
 PLCA executes the writing on the three LEDs (ACTIVE, STAND-BY and INACTIVE) from the
PLC A sector.
 PLCA executes the writing on the RL B relay, used to switch off PLCB.
 PLCB executes the STAND-BY and INACTIVE buttons reading in the PLC B sector.
 PLCB executes the TURN ON PLC A button reading.
 PLCB executes the writing on the three LEDs (ACTIVE, STAND-BY and INACTIVE) from the
PLC B sector.
 PLCB executes the writing on the RL A relay, used to switch off PLCA.

ALTUS Nexto NX3004 Specifications

General

Brand	ALTUS
Model	Nexto NX3004
Category	Processor
Language	English