Automation

Controls – Automatic Control Devices
Programmable Logic Controllers – PLCs
Internet of Things (IoT) – Info
Links – Automation Manufacturers

What is Industrial_Automation?

Automation is the use of technology to minimize human input related to perform tasks.

Gains in quality, accuracy, and precision can usually be obtained while minimize costs and downtime. These days industrial automation is simply a requirement in any industry.

Automation Field Buses

Field buses network the programmable logic controller (PLC) to multiple devices on real-time bus instead of individual point-to-point control links.

List of Network Buses
All About Field Buses
List_of_Automation_Protocols

Point-to-Point Links

4–20 mA – Point-to-point low-current process control loop.
https://en.wikipedia.org/wiki/Current_loop
Electrically replaces the earlier highly successful 3–15 psi pneumatic control signal standard popular in the 1950’s. Uses the current through two wires to control process control equipment. Circuit must be DC capable.

RS-232 – Point-to-point low-speed serial data link using unbalanced signaling.
https://en.wikipedia.org/wiki/RS-232
Uses a minimum of three wires for Transmitted Data (TXD) and Receive Data (RXD) along with a ground (GND). Can be -15V to +15V or ran down to -3V to +3V but must withstand open circuit voltages of -25 Volts to +25 Volts.

RS-485 Fieldbuses

RS-485 – Point-to-point, multi-dropped, and multi-point high-speed serial link using differential signaling
https://en.wikipedia.org/wiki/RS-485
Used for computer and industrial automation systems and protocols. Uses a minimum of three wires with data transmitted over the A/D- and B/D+ wires (usually together as a twisted pair) with the C/SC/G wire used as a ground reference (but technically could use 5 wires for full-duplex). Uses a termination resistor at each of the cable based on the cable impedance as part of a resistor bias network to pull-up/pull-down the data lines to default values. Uses a 0 Volt to +5 Volt signal and each line should be -7 Volts to +12 Volts tolerant.

BITBUS – Created by Intel Corp
http://www.bitbus.org/fprimer.htm
http://www.bitbus.org/dnl/bapi.pdf
Oldest commonly used field bus technology. Uses one differential pair for data and a second for a clock pair along with a common ground wire and a third pair for RTS if repeaters are used.

Modbus RTU – Published by Modicon (now Schneider Electric)
https://en.wikipedia.org/wiki/Modbus
https://modbus.org/
A de facto standard communication protocol that’s openly published, royalty-free, and is available on many devices. Uses one differential pair for data along with a common ground wire.

Profibus DP – Developed by German Government, modified by Siemens
https://en.wikipedia.org/wiki/Profibus
https://www.profibus.com/
It’s one of the most installed fieldbuses in the world. Uses one differential pair for data along with a common ground wire.

INTERBUS – Developed by Phoenix Contact
https://en.wikipedia.org/wiki/INTERBUS
http://www.interbusclub.com/
It’s one of the leading and most installed fieldbuses in the world. Uses one differential pair for transmit and a second differential pair for receive along with a common ground wire.

CAN Fieldbus

CAN Bus – A Controller Area Network Bus
https://en.wikipedia.org/wiki/CAN_bus
https://en.wikipedia.org/wiki/CAN_FD
Traditionally found in automobiles but has spread to other domains. CAN is a multi-master serial bus standard for connecting two or more nodes on a CAN network. Physically it’s a differential wired-AND signal bus over CAN High (CANH) and CAN Low (CANL) wires. It’s usually 0 Volts to +5 Volts with <100 to 120 Ohm terminations at each end and should be −27 Volt to +40 Volt tolerant.

DeviceNET – Developed by Allen-Bradley (now owned by Rockwell Automation)
https://en.wikipedia.org/wiki/DeviceNet
https://www.odva.org/
An open fieldbus standard based on the CAN protocol. Uses one differential pair for data along with a common ground wire. Has been superseded and incorporated into Common Industrial Protocol (CIP).

Ethernet FieldBuses

Ethernet – Used to connect devices with RJ45 connectors.
https://en.wikipedia.org/wiki/Ethernet
https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair
https://en.wikipedia.org/wiki/Industrial_Ethernet
Ethernet is logically a shared bus medium especially over coaxial cable or when using hubs, although newer implementations use a physical star topology with switching over two twisted pairs or more commonly four twisted pairs of copper wires or fiber optic links.

Modbus TCP – Published by Modicon (now Schneider Electric)
https://en.wikipedia.org/wiki/Modbus
https://modbus.org/
A de facto standard communication protocol that’s openly published, royalty-free, and is available on many devices.

ProfiNET – Developed by German Government, modified by Siemens
https://en.wikipedia.org/wiki/Profinet
https://www.profibus.com/
Real-time Ethernet protocol that evolved from and is backwards compatible with Profibus DP using an appropriate proxy.

EtherCAT – Invented by Beckhoff Automation
https://en.wikipedia.org/wiki/EtherCAT
https://www.ethercat.org/
Ethernet-based fieldbus system featuring low cycle times and low jitter.

EtherNet/IP – Developed by Allen-Bradley (now owned by Rockwell Automation)
https://en.wikipedia.org/wiki/EtherNet/IP
https://www.odva.org/
It’s one of the leading industrial protocols in the United States. Has been superseded and incorporated into Common Industrial Protocol (CIP).

Automation Gallery