Altus has connectivity to all levels of communication. Control system is usually divided into three levels of communication: Plant Level, Control Level and Field Level.
Plant Level Network
At Plant Level it is necessary to maintain a global database, collect, process, store and manage various types of data. That is where the basic production plan is established and diagnoses of elements of the same level and below are made. The typical number of nodes is from 2-20, and transfers take place at a speed of 10 to 60 seconds. Messages are sent via megabytes, and there is no need for determinism in the network (the time to complete the messages is not subject to a maximum limit).
Plant Level Network must offer high reliability, be of simple architecture and sound-proof within reasonable standards. The technologies applicable hereto are Ethernet (IPX, TCP / IP) according to IEEE 802.3 Standard, Level 1.
Altus Ethernet TCP/IP Network
Through the Ethernet network interfaces, the Altus Programmable Controllers can connect them using the TCP / IP layer that enables full access to the plant information. In addition to the proprietary protocols already established in the market as Alnet II / TCP, Altus provides "drivers" of communication using open platforms such as Modbus RTU, Modbus / TCP and OPC Server. By using either Monitoring Systems or computer systems of higher hierarchy, the control applications can be accessed in a standardized manner, expanding the potential of connectivity.
You can also provide Web page server, database support with Event Log and it is possible to send e-mails.
The PO7094, Interface Ethernet Modbus / TCP and Alnet II / TCP are examples of Ethernet Interface for Ponto Series. They allow the connection between Altus CPs and opened communication networks that meet the TCP / IP standard. They allow the communication with any other equipment that communicate through the TCP / IPE Ethernet protocol, with ALNET II or MODBUS application level, as well as to use both protocols simultaneously. Besides allowing for Web pages and server database.
AL-2785, OPC ETH ALNET II Communication Driver, is an OPC Server communication driver for Altus Programmable Controllers. It allows for communication with software that implements OPC Client communication interfaces, such as tools for monitoring and control of processes.
Control Level Network
The Control Level is responsible for the equipment that make up the production line, as well as for the drive and reading of all the signs of the field. This is where the calculations of control and optimization algorithms are made, as well as data acquisition, monitoring of processes and alarm logs. The core of production quality control is at this level. Messages are sent via kilobytes and determinism is necessary to ensure minimum time for control actions. The transfer frequency in such case is 1/10 ms to 1/10s.
Control Level Network must offer high reliability, have a more complex architecture and be highly soundproof within reasonable standards. The applicable technologies are mostly proprietary and they tend to meet MAC (ISO 802.3), LLC (IEEE 802.2 Class I).
ALNET II Network
Developed from AL-2000/MSP Series Programmable Controllers ("Multi-Station Processors") ALNET II is a multi-master network and allows for distributed control from multiple processors in a deterministic way, through the RS485 interface. It reaches a speed of 1 Mbaud. Its concept is based on subnets, and its architecture allows for distributing and isolating the traffic of information in applications.
Its performance allows for the actual distribution of control tasks among several PCs. It provides gateways for various types of connections, which allows it to be compatible with environments developed with products of other brands.
With the advent of Ethernet in industrial environment, one can use the Alnet II network in this physical environment. Thus, the advantages of the Alnet II protocol are associated with Ethernet.
Benefits of using the Alnet II / TCP Network:
- Possibility of star, ring or hybrid topologies, allowing to associate them to get a model that best suits the application
- Interconnection between AL-2000, Ponto and Nexto Series PCs
- Increase in number of nodes on a network
- Use of market standard industrial switches, hubs and routers standard
- Allow for uploading and downloading of applications from PCs via ethernet network, according to the criteria for levels of access (users x password)
- Availability of simultaneous access to the application of PCs and control variables for different computers
- Ease of maintenance and it can make use of IT tools for diagnoses inherent to Ethernet networks
The main modules for use of this protocol are PO7094, AL-3412 (Ethernet 10/100 Mbit/s interface) for AL-2000 Series, and AL-3414 (Redundant Ethernet interface with Modbus / TCP and Alnet II / TCP) for AL-2000 Series.
ALNET I Network
ALNET I is a master-slave monitoring network, for data analysis and acquisition, used in the entire line of Altus Programmable Controllers. It helps implement control networks when applied in conjunction with the ALNET II network. Its protocol is open and available to develop any kind of software driver. It can control up to 31 PCs from a master station.
The ALNET I is also used by Mastertool Extended Edition (MT8000) to exchange data and program the Ponto and AL-2000 Series.
Modbus RTU and Modbus TCP Network
Besides the proprietary protocols (ALNET I and ALNET II) for control network, the Altus PCs can also work with open protocols, such as Modbus RTU and Modbus / TCP.
Modbus RTU is a master-slave-type network, which provides only one controller as master of the network. As for Modbus/TCP, it is a Client/Server network which makes it possible for more than one user to access variables from other devices (server) simultaneously.
These networks enable integration between Altus controllers and other intelligent electronic devices (IEDs) such as Human-Machine Interfaces (HMIs).
Among the PCs using Modbus are DUO, Ponto, AL-2000, FB, Nexto Series, as well as H and Exter HMI Series.
The PO7094 and AL-3414 modules provide Modbus protocol to Ponto and AL-2000 Series, respectively. For Nexto Series, the NX5000 module can be used. For FBs Series, the CBE module.
Field Level Network
The field level is used to acquire process variables, send programming set-points, acquire condition of equipment, performance on motors, valves and other equipment. The typical number of nodes per level is 50-500, with transfer times of about 1/ms to 1/100 ms. Messages speed vary from one bit to some bytes, and determinism is required.
PROFIBUS is an open field network of international use, as defined in EN 50170 Standard. The DP version is mostly used for Field Level. For further information on the PROFIBUS versions, please visit the Profibus Association website: www.profibus.org.br.
The PROFIBUS DP protocol is optimized for fast and economical connection. This version is especially designed for communication between automation control systems and distributed I / O. Moreover, it can be used to replace signal transmission, such as 24 Vdc or 4-20 mA.
In cases of installations in intrinsically safe areas, or classified areas, in accordance with the IEC 1158-2 international standard, PROFIBUS PA can be used via gateways (DP/PA).
An example of PROFIBUS DP topology is to use AL-2000 Series for controlling input/output (I/O) of Ponto Series. For this purpose, you can use AL-3406 (Interface of Profibus Master Network) for AL-2000 Series, and PO5063V1 (Interface of Profibus DP Slave Network) to Ponto Series.
In future applications, when PC needs to be updated, in the case above, it is possible to replace AL-2000 Series with Nexto Series. Thus, the main controller would be replaced while the E / S of Ponto Series would be kept. For that, NX5001 (Profibus Master Network Interface) for Nexto Series should be used.
The use of open protocols allows the user to make upgrades without having to change the architecture or replace IEDs in good condition, in addition to providing these upgrades with support.
Benefits of using the Profibus DP network with Altus products
- High performance on communication (12Mbps up to 100 meters)
- Hot-Swap for all modules of the Point Series remote
- Highly diagnosable. It is possible to obtain information at I/O level
- Profibus Gateway to Alnet I functionality. This facilitates the use of local HMIs using Alnet I protocol . The PO5063V1 interface, besides the Profibus communication channel, has an Alnet I serial port capable to traffic data sent from Profibus network
- Possibility of redundant configurations: Double Master, Double Slave, bus or ring Optical Networks
- Expand networks without the need to stop the process, among others
Using Modbus RTU and Modbus TCP Network at Field Level
In cases where cost is critical and there is no need for features such as PROFIBUS mentioned above, the solution might be to use Modbus network as Field network.
An architecture with a medium-sized CPU, as PO3247 of Ponto Series, can be made, by using the FBs Series as remote I / O.
Benefits of using the Modbus RTU network with Ponto PCU and Remote FBs
From the standpoint of Ponto Series CPU PO3247
- Programming via USB
- Communication speed up to 115Kbps in RS232, RS485 and USB
- Alphanumeric display for indication of the diagnosis in writing, directly in front of the CPU
- Hot-swap of local I/O modules
- Greater processing power (for it has two processors). One of them is responsible for arithmetic calculations, making it directly in hardware
- Modbus RTU open protocol, master and slave in RS232 and RS485
- 16-bit-PID Function
From the standpoint of FBs Series Remote Modbus RTU
- Low Cost
- Communication speed up to 115Kbps in RS232 and RS485
- Analog and Digital Inputs with Filters
- 14-bit-Analog Inputs
- Over 500 points of I / O for remote
- Modbus RTU open protocol, master and slave in RS232 and RS485
HART is an open protocol, run by HART Communication Foundation. It was designed to enable predictive maintenance and remote parameterization of process analog devices such as transmitters and valves in the 4-20 mA standard current.
Historically, the digital information (HART) is separated from the analog information (4-20 mA) through auxiliaries devices, known as HART multiplexers. Conventional I/O modules (4-20 mA) of Programmable Controllers for analog information are also used.
The PROFIBUS open field network, maintained by PROFIBUS organization, defined the PROFIBUS DP-V1 protocol, as well as the profile HART on PROFIBUS, as a conveyor of HART information to higher levels of the plant, in an acyclic way and without compromising the performance of cyclic tasks of I/O transfer. Thus, remote PROFIBUS DP-V1 with I/O HART modules and HART on PROFIBUS profile dispense with HART multiplexers, reducing costs, number of field networks, terminals and space on panels. It also increases the reliability due to reduction of components and communication networks.
To meet this requirement, Altus offers two I / O modules (PO1114 and PO2134, analog input and output respectively) and two PROFIBUS buses (PO5064 and PO5065, for simple and redundant topology respectively) that allow one to use the HART on PROFIBUS architecture.
Benefits on using Hart Network with Ponto Series
- Current measurement of 0-20 and 4-20mA, 16bit
- HART Protocol (4-20mA)
- Insulation for both logic and external source
- Local and remote diagnosis
- Hoty swapping, without interfering with panel wiring
- Remote parameterization via software
- Analog points galvanically insulated from logic
- Filters configurable by software
- Automatic addressability of modules
With a unique architecture, which includes a synchronism network, Altus Programmable Controllers can remain synchronized at 1 ms even when distributed over a heavily equipped network. This capability enables to solve process data acquisition problems for analysis of events with this degree of resolution.
Counting on I/O that also respond at this speed range, the Altus solution for acquisition and logging of events is unique in the PC market.