ALTUS Nexto NX3004 User Manual

6. Redundancy with NX3030 CPU
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 For downloading off-line a different project in the Non-Active PLC, as described in the
Exploring the Redundancy for Off-Line downloading of Modifications without Interruption of
the Process control section
 For monitoring or forcing the non-redundant variables in the Non-Active PLC
Redundancy Diagnostics on the NX3030 CPU Graphic Display
Many diagnostics related to redundancy can be observed on the NX3030 CPU display.
CPU Redundancy State
The PLC redundancy state, described in Redundant CPU States is seen in the three initial characters
on the main screen second line, as shown in the chapter Graphic Display. The display screen is
presented on initialization and again a few seconds after the navigation is finished (without pressing
the NX3030 CPU button).
Screens below the REDUNDANCY Menu
There’s a menu called REDUNDANCY, where below it there are several screens. The description
and access of theses screens are available in the Configuration – CPU’s Informative and
Configuration Menu chapter.
Redundancy Diagnostics Structure
The NX4010 module diagnostics area is mapped over direct representation %Q variables, and
defined symbolic through the AT directive, in the GVL Diagnostics.
This section is divided in two parts:
 DG_NX4010.tGeneral: General diagnostics for NX4010 operation. They are described in the
Redundancy Link Module Technical Features – CE114900
 DG_NX4010.tRedundancy: Redundancy specific diagnostics which are described within the
chapter. This item is divided in other 6 data structures:
o RedDgnLoc: Has redundancy diagnostics of the local PLC (connected), e.g. the PLC
redundancy state. This section is described in Redundancy Diagnostics
o RedDgnRem: It’s a copy from the other PLC RedDgnLoc, received through Synchronism
channels NETA / NETB. This way the local PLC has access to the remote PLC diagnostics.
This section is described in Redundancy Diagnostics
o RedCmdLoc: Has redundancy commands generated in this PLC (local), for instance, through
write commands from a SCADA system or generated in POUs in this PLC (ActivePrg or
NonSkippedPrg). This section is described in Redundancy Commands
o RedCmdRem: It’s a copy from the other PLC (remote) RedCmdLoc, received through
Synchronism channels NETA / NETB. This section is described in Redundancy Commands
o RedUsrLoc: Used to allow the user to exchange information between PLCA and PLCB. This
section is described in User Information Exchanged between PLCA and PLCB
o RedUsrRem: Used to allow the user to exchange information between PLCA and PLCB. This
section is described in User Information Exchanged between PLCA and PLCB
It is important to stress that the redundancy diagnostics structures are refreshed only when occurs,
with success, a new data synchronization. Therefore, until a new synchronization doesn’t occur, the
diagnostics will remain with the last read value.
Furthermore, the diagnostics structures from the remote PLC are read only, that is, values written to
these structures will be overwritten in the next synchronization. Thus, is not possible to use the
RedCmdRem structure to execute a command in the remote PLC. Always use the structure
RedCmdLoc to execute commands.

ALTUS Nexto NX3004 Specifications

General

Brand	ALTUS
Model	Nexto NX3004
Category	Processor
Language	English