The document discusses industrial communication infrastructure and protocols. It covers: - Reliable infrastructure is critical for optimal network performance in industrial plants. - Many industrial plants have transitioned to Ethernet networks to increase reliability and lower costs. - Components must be rugged to withstand harsh industrial environments, including cables, switches, wireless systems and more. - Serial communication standards like RS-232, RS-422, RS-485 and protocols like Modbus are commonly used for industrial automation. These define electrical characteristics, cabling, and connectivity to enable reliable communication. - TCP/IP model layers include application, transport, internet and network access layers to transfer data between devices using standards like Ethernet IP, Pro

1. INDUSTRIAL COMMUNICATION :
RS232/422/485-MODBUS
SUBMITTED BY
Aswathy S

2. COMMUNICATION INFASTUCTURE
■ Communication infrastructure refers to the backbone of the communications system
upon which various broadcasting and telecommunication services are operated.
■ This can be built from copper cable, fiber, or wireless technologies utilizing the radio
frequency spectrum, such as microwave and satellite.
■ The infrastructure is the core component that connects upstream production, such
as voice, data and audiovisual services, with downstream consumers.

3. INDUSTRIAL COMMUNICATION
INFASTRUCTURE
■ Industrial plants rely heavily on their automation, instrumentation and control
data communications to relay signals between machinery, devices and control
systems to activate events on an exacting and pre-determined schedule, with
little or no margin for error.
■ No matter what the industry, if a switch, connector or cable should fail,
replacing the part represents only a fraction of the costs associated with
production downtime.
■ Depending on the industry, and the size and nature of the business, indirect
costs can range from tens of thousands to hundreds of thousands of dollars.
■ That’s why a reliable infrastructure architecture is critical to optimal network
performance.

4. The move to industrial Ethernet
■ Over the past decade, many leading manufacturers and processors have
made the transition from PLC- and PC-based plant floor information systems
to an open, integrated Ethernet network.
■ built on the same LAN standard (ANSI/TIA/EIA-568B) that has been used in
commercial offices for decades.
■ Typically, their goals include increased reliability, consistent high
performance, greater ease of maintenance and lower total cost of ownership.

5. CABLES AT RISK!!!
■ Many if not most cables, switches and other network components integral to
machinery automation and control are located in harsh and potentially hazardous
environments
■ Environments that are commercial off-the-shelf (COTS) ..
■ Ethernet systems are not made to withstand. Only environmentally hardened,
industrial-grade Ethernet component are tough enough to handle such conditions

6. TIPS FOLLOWED!
■ Following are some guidelines and best practices that IT teams, industrial network
designers and integrators used to follow in designing and specifying an industrial
communications network capable of delivering close to 100 percent uptime.
– Temperature Extremes
– Chemical Exposure
– Humidity Levels
– UV Radiation Exposure
– Physical Hazards.

7. BEST POSSIBLE WAYS
■ The best way to optimize the performance and long-term reliability of the plant floor
Ethernet
– with ruggedly built cabling,
– connectivity
– hardware components designed specifically for use in harsh industrial
settings.
■ These products are designed and engineered to provide a lifespan similar to that of
other automation system components – typically 10 to 30 years, which is
significantly more than COTS products can deliver.

8. Rugged components to fit each
application
■ Environmentally hardened components for the physical media layer – cabling and
connectivity .
■ Include both industrial-grade Cat 5e and Cat 6 copper-base cables and heavy-duty,
indoor/outdoor optical fiber cables.
■ Up jacketed and armored cables offer extra protection in extreme environments.
■ Continuous flex cables are designed for use with robotics and mechanized
machinery, and rugged variable frequency drive (VFD) cables can be used to save
energy, while extending the lifespan of motorized equipment.
■ Connectivity components include industrial-grade cordsets, patch cords and
connectors, modular jacks and plug kits, faceplates and surface-mount boxes – all
built to last in harsh and demanding environments.

9. ■ On the hardware side, components include ruggedly built managed and unmanaged
switches in a variety of copper/fiber port configurations, port densities, mounting
options, and industry certifications.
■ There are firewall appliances to secure and protect the network while still permitting
authorized communications to pass through.
■ And there are safe and secure industrial wireless systems and software, hardened
power supplies, SFP fiber transceivers, and more.
Rugged components to fit each
application

10. FUTURE
■ A factor frequently overlooked in maximizing network reliability is REDUNDANCY,
■ Which is especially important in mission-critical applications. Two aspects of redundancy
are key to maintaining uninterrupted signal transmission and maximum uptime.
■ The first is power source redundancy.
Specifying switches that have dual power input capabilities means that if one
power source fails, the other immediately takes over.
■ The second is data path redundancy.
The daisy-chain network topologies used by many industrial plants to connect
automated machinery and devices have one inherent flaw – if any link between
two switches fails, the entire system could potentially go down, as the devices
on one network segment can no longer communicate with devices in other
segments. The solution is to ensure a built-in redundant data path into the network
topology.

11. What Is Serial Communication?
■ Serial communication is a communication method that uses one or two
transmission lines to send and receive data, and that data is continuously sent and
received one bit at a time.
■ Since it allows for connections with few signal wires, one of its merits is its ability to
hold down on wiring material and relaying equipment costs.

12. MODES
■ The transmission modes are classified as
– Simplex
– Half Duplex
– Full Duplex.
■ There will be a source (also known as a sender) and destination (also
called a receiver) for each transmission mode.

14. CONT.
■ Simplex method is a one-way communication technique.
– Only one client (either the sender or receiver is active at a time). If a
sender transmits, the receiver can only accept. Radio and Television
transmission are the examples of simplex mode.
■ Half Duplex mode,
– both sender and receiver are active but not at a time,
– i.e. if a sender transmits, the receiver can accept but cannot send and
vice versa.
– A good example is an internet. If a client (laptop) sends a request for a
web page, the web server processes the application and sends back the
information.
■ Full Duplex mode
– It’s is widely used communication in the world.
– Here both sender and receiver can transmit and receive at the same
time. An example is your smartphone.

15. SERIAL COMMUNICATION STANDARDS
■ In embedded system, Serial communication is the way of exchanging
data using different methods in the form of serial digital binary.
■ Some of the well-known interfaces used for the data exchange are
– RS-232,
– RS-485,
– I2C,
– SPI etc.

16. MODBUS
■ Modbus is a communication protocol developed by Modicon systems. In simple
terms, it is a method used for transmitting information over serial lines between
electronic devices.
■ Its an open protocol so the specification are published.
Request ,slave , master, transport layer security
■ In a standard Modbus network, there is one Master and up to 247 Slaves, each with
a unique Slave Address from 1 to 247. The Master can also write information to the
Slaves

17. MODBUS VARIATION
■ Used with serial and Ethernet cable
■ Modbus have variation
1. ASCII : Binary codes
2. RTU : Remote Terminal Unit . RS232 /422/485
3. TCP/IP : Packet message transfer

18. MODBUS COMMUNICATION

19. MODBUS COMMUNICATION PROTOCOL
 The device requesting the information is called the Modbus Master and the devices supplying
information are Modbus Slaves.
 CRC stands for Cyclic Redundancy check. It is two bytes added to the end of every modbus
message for error detection.
 The receiving device also calculates the CRC and compares it to the CRC from the sending
device. If even one bit in the message is received incorrectly, the CRCs will be different and an
error will result.

20. what is RS232
■ In telecommunications, RS-232, Recommended Standard 232 is a standard originally
introduced in 1960 for serial communication transmission of data.
■ It formally defines signals connecting between a DTE (data terminal equipment) such as
a computer terminal, and a DCE (data circuit-terminating equipment or data
communication equipment), such as a modem.
■ The standard defines the electrical characteristics and timing of signals, the meaning of
signals, and the physical size and pin out of connectors.
■ The RS-232 standard had been commonly used in computer serial ports and is still widely
used in industrial communication devices.

21. Application

22. Advantage And Disadvantage
 Half duplex communication.
 The large voltage swings and requirement for positive and negative supplies increases
power consumption of the interface and complicates power supply design. The voltage
swing requirement also limits the upper speed of a compatible interface

23. Advantage And Disadvantage
■ Single-ended signaling referred to a common signal ground limits the noise
immunity and transmission distance.
■ Multi-drop connection among more than two devices is not defined. While multi-drop
"work-arounds" have been devised, they have limitations in speed and compatibility.
■ The standard does not address the possibility of connecting a DTE directly to a DTE,
or a DCE to a DCE

24. RS 422
■ The full name of the RS-422 standard is “the electrical characteristics of the balanced
voltage digital interface circuit”, which defines the characteristics of the interface circuit.
■ There is actually a signal ground, a total of 5 lines. Since the receiver uses high input
impedance and the transmission driver has a stronger driving capability than RS232, it
is allowed to connect multiple receiving nodes on the same transmission line, and up to
10 nodes can be connected.
■ One master device (Master) and the rest slave devices (Slave), the slave devices cannot
communicate with each other, so RS-422 supports point-to-multidirectional two-way
communication.
■ The receiver input impedance is 4k, so the maximum load capacity of the transmitter is
10 & TImes; 4k + 100Ω (terminating resistor).
■ It uses twisted pair cable for reducing noise.
■ It uses the signal balancing.

25. Feature
■ Since the RS-422 four-wire interface uses separate transmit and receive channels, there
is no need to control the data direction.
■ Any necessary signal exchange between devices can be done in software mode
(XON/XOFF handshake) or hardware mode (a pair of separate pairs). Stranded wire).
■ The RS-422 has a maximum transmission distance of 4000 feet (about 1219 meters)
and a maximum transmission rate of 10 Mb/s.
■ The length of the balanced twisted pair is inversely proportional to the transmission rate,
and it is possible to reach the maximum transmission distance below the 100 kb/s rate.
■ The highest rate transmission is only possible at very short distances. The maximum
transmission rate that can be obtained on a typical 100-meter twisted pair is only 1 Mb/s.
■ RS-422 requires a terminating resistor that requires a resistance equal to approximately
the characteristic impedance of the transmission cable.
■ In the short-distance transmission, there is no need to terminate the resistor, that is,
generally no need to terminate the resistor below 300 meters. The terminating resistor is
connected to the farthest end of the transmission cable.

26. Real time implementation

27. RS 485
■ RS 485 is a improved version of RS 422 , it over come the limitation of mluti-drop
up to 32 device.
■ The RS-485 serial bus is widely used when the communication distance is required
to be several tens of meters to several kilometers.
■ RS-485 uses balanced transmit and differential receive, so it has the ability to
reject common-mode interference.
■ In addition to the high sensitivity of the bus transceiver, it can detect voltages as
low as 200mV, so the transmitted signal can be recovered beyond the kilometer.
■ RS-485 uses a half-duplex mode of operation, and only one point can be sent at
any time. Therefore, the transmitting circuit must be controlled by an enable signal.

28. Features
 Electrical characteristics of RS-485: The logic “1” is represented by the voltage
difference between the two lines +2V~+6V, and the logic “0” is represented by the
voltage difference between the two lines -6V~-2V.
 The interface signal level is lower than RS-232-C, and it is not easy to damage the
interface circuit chip, and the level is compatible with the TTL level, which is convenient
for connection with the TTL circuit. The highest data transmission rate is: 10Mbps.
 The RS-485 interface adopts a combination of balanced driver and a differential
receiver, which has strong anti-common mode interference capability, that is, good anti-
noise performance.
 The maximum transmission distance of the RS-485 interface is 4000 feet, which is
actually up to 3000 meters.
 The RS-232-C interface allows only one transceiver to be connected to the bus, ie single-
station capability; while the RS-485 interface allows only up to 128 transceivers to be
connected on the bus, ie multi-station capability, so that the user The device network can
be easily established using a single RS-485 interface.

29. Real time example

30. Comparative study

31. TCP/IP
■ Transmission control protocol / internet protocol : TCP/IP MODEL
■ Conceptualized in form of layers

32. ■ 5 layer – Application layer ,transport layer, internet layer, Network access layer
TCP/IP

33. Application Layer _ Layer 5
■ Application layer provides an interface with human (network application user) and
the network. Thus, Application layer provides an interface between the network
applications and other lower layers of TCP/IP protocol stack.
■ Standard protocol and working at application layer
- Gives domain name
- HTTP_ Hypertext Transfer Protocol , SMTP_ simple Mail Transfer Protocol

34. DOMAIN NAME

35. Transport layer _ layer 4
■ Application layer gets data from the program it communicate to the transport layer
through ports
■ Transport layer have two protocol UDP or TCP.
■ UDP is unacknowledged (used in valve)
■ Data is turned to the packets and TCP slaps a header on what order to resemble the
packets
■ Error checking is done.

36. Internet layer _ Layer 3
■ Create IP , it actually the address where to be send data and address of the reciever
data

37. Network access layer
■ MAC addressing
■ It works with hardware and converting these Data to electrical signal
■ Packet switching
■ UDP : It is unacknowledged and usually used for valves
■ TCP : It is acknowledged usually used for writing to RAM
■ MOSTLY USED
- Modbus TCP : It does not use UDP . It directly goes to TCP then IP finally Ethernet packet
- Ethernet IP : it uses both TCP and UDP .I/O messages uses UDP
- Profinet : Directly goes to packet
How Ethernet TCP/IP is Used by Industrial Protocols

38. LAYER

39. Thank you