1. INTRODUCTION
the module NX4010
The Figure
shows an example of minimum configuration of a redundant PLC, that can be used with the NX9000 rack.
Figure 14: Minimum Configuration of a Redundant PLC
1.1.4.11.
CPU & Network Interface Modules Redundancy
As shown in the previous diagram, this architecture has network modules with protocols based on Ethernet. There are two
network modules for each purpose: a control network for CPU to CPU communication and a supervision network for SCADA
and OPC usage. Both half clusters must have two interfaces for each network, forming a full redundant system with CPU,
network interface and physical layer redundancy.
1.1.5.
Main Features
1.1.5.1.
CPUs
The CPUs have many integrated functions, online programming, high memory capacity and many serial channels. These
devices are powered by latest 32-bit CPUs allowing outstanding performance and integration of many features. Even the
simplest CPU version has an Ethernet port for programming, use in MODBUS TCP networks and embedded web server. The
CPUs NX3010, NX3020 and NX3030 have two serial interfaces for connecting local HMIs and MODBUS networks, they also
have a storage card slot for hosting web pages, application source code and other user files. The CPUs NX3003, NX3004 and
NX3005 have one serial interface for connecting local HMI and MODBUS network and does not have memory card slot. All
CPUs have web pages with complete status and diagnostics list, firmware update, and other features.
1.1.5.2.
Modules
The modules carry high density I/Os. Nexto Series delivers two module form factors – slim and full size modules – allowing
the best I/O combination for many applications where high-density and panel size can be an issue. Every I/O module has a
display for local diagnosis, where each I/O point state is presented. There is also multifunctional diagnosis about the module
status. All diagnostics information is also accessible remotely by CPU, fieldbus head or by MasterTool IEC XE configuration
tool.
The Nexto I/O modules with frontal cover have labels where the user can identify the modules and the terminal blocks.
1.1.5.3.
High-Speed Backplane Bus
Nexto Series architecture has a state-of-the-art 100 Mbps Ethernet based backplane bus. This backplane bus has real-time
behavior, allowing predicted and cyclic data exchanges. The high throughput enables the update of large quantities of inputs
in a short time window. Besides, time critical applications like motion control are possible with this technology. The modules
are addressed and identified automatically, avoiding errors during application setup and field maintenance. The backplanes
NX9000, NX9001, NX9002 and NX9003 provide special features in order to allow CPU redundancy in the same rack or in
different racks using the Redundancy Link Modules:
Automatic module addressing and identification
Hot-swap (except NX9010)
100 Mbps Ethernet-based serial bus
Extremely accurate time synchronization for I/O update or time stamping
Single chip hardware solution
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