Industrial Ethernet is suitable for factory automation and control, process automation, building automation and many other industrial applications. One of the advantages of Industrial Ethernet compared to standard Ethernet is deterministic real-time data exchange and synchronization cycle times of less than 1 ms.
More than 20 Industrial Ethernet protocols are deployed as standard and used in industrial applications: these include EtherCAT, Sercos III, PROFINET, EtherNet/IP and Ethernet Powerlink. Why are there so many standards to choose from? The reason is that every manufacturer of industrial equipment seems to know that real-time data exchange via Ethernet is better, and has set its own standards based on their knowledge of the past serial fieldbus field.
Most Industrial Ethernet standards cannot be implemented with standard Ethernet Media Access Control (MAC); they require an Application Specific Integrated Circuit (ASIC) or a dedicated Field Programmable Gate Array (FPGA). This is because the Ethernet frame is received instantaneously (also known as the "shortcut method"), meaning that when the frame is received on the first Ethernet port, the frame has been processed and used by the dedicated Industrial Ethernet. The MAC hardware block is transferred to the second Ethernet port. With the shortcut method, port-to-port delays of less than 1μs can be achieved for Ethernet frames.
On the other hand, standard Ethernet MAC uses a method of storage and forwarding. The complete Ethernet frame must first be received, and then the Ethernet MAC can then perform any processing or forwarding of the frame. This adds jitter and delay to the frame, so it is not a good choice for industrial equipment manufacturing.
The Programmable Real-Time Unit and Industrial Communication Subsystem (PRU-ICSS) provide great flexibility to support a variety of Industrial Ethernet protocols, but these are discussed in more detail later.
Sercos has been in the field of factory automation applications (suitable for mechanical engineering and construction) for 25 years. Sercos III is a third-generation agreement developed in 2003. This highly efficient and deterministic communication protocol combines the real-time data exchange of the Sercos interface with Ethernet. So far, Sercos III technology integration has only been implemented in FPGAs.
A Sercos III master can control multiple Sercos III slaves (such as drivers, sensors, and analog and digital I/O devices) – as shown in Figure 1. A master device can control up to 511 slave devices.
Figure 1: Example Sercos III Network Ring Topology
A key advantage of Sercos III is that it supports a ring topology next to a line topology. If the Ethernet Cable fails, the Sercos III network can switch to a line topology, allowing the master to continue communicating with all slaves in the network. Once the Ethernet cable has been repaired, the master can switch the Sercos III network from a line topology to a ring topology.
The communication protocol is time division multiplexed as shown in FIG. Within a Sercos III communication cycle there is a time slice dedicated to real-time Sercos III frames called the Real Time (RT) channel. In this time slice, the master and slave devices can exchange process data for use within a programmable logic controller (PLC). In a second time slice called the Unified Communications Channel (UCC), all devices (master and slave) within the network can exchange standard Internet Protocol (IP) messages. UCC can be used to exchange information about a Web server, update device software with Simple File Transfer Protocol (TFTP), or transmit Ethernet frames for IP-based applications (any kind).
Figure 2: Sercos III Time Division Multiplex Communication Cycle
Using FPGAs with Sercos III adds cost and board space. An alternative solution to eliminate cost increases is to use PRU-ICSS, a peripheral that is available in many TI Sitara processors. For example, TI offers PRU-ICSS firmware for AM335x processors, enabling Sercos III slaves without the need for an external FPGA. The solution can be evaluated using the TMDSICE 3359 evaluation board as seen in Figure 3.
Figure 3: TMDSICE3359 Industrial Communication Development Platform for Sercos III
Other than normal 5v/12v/24v wall Adapter, Yidahun also can produce 9V wall adapter.
9V Wall Charger are wall plug adapters with 9V output, the normal dc plug size 2.5*0.7mm, 3.5*1.5mm, 5.5*2.5mm, 5.5*2.1mm, mini USB and MICRO USB etc.
Yidashun wall power adapter are uitable for HD player, DVD, LCD TV, surveillance camera, LED display, LED light, USB hub, SDSL, repeater, radio, Speakers, Disk driver etc. and also Yidashun can customize the power adapter according to customer's request
There are different plugs for choose like: EU plug, US plug, UK plug, Australia plug, Argentina plug and Brazil plug etc which used in different countries. Customers can buy any plug wall adapter from Yidashun.
9V Wall Charger,9V USB Wall Charger,9V Portable Wall Charger,9V Wall Mount Adapter
Shenzhen Yidashun Technology Co., Ltd. , https://www.ydsadapter.com