Communication between DCS and PLC
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I would like to ask experts how communication between DCS and PLC is achieved?
In the case of servers, OPC can handle everything. If a hard connection to the controller is required, then programming using Modbus, buffers, and similar methods is necessary (depending on the brand). Of course, there are also many advanced solutions that offer features like MMS
How to configure communication between DCS and PLC?
For the same brand, one configuration software is used; for different brands, software such as KingView or WinCC can be employed. As for communication, the DCS side is equipped with an intelligent network communication card (which is necessary), and the PLC has communication cables connected to this card. After making the appropriate settings, the intelligent instruments can be seen in the diagnosis interface. If you are familiar with one type of DCS and PLC, and then seek technical support from suppliers for guidance, your skills will improve rapidly
If the DCS has IO services, it is possible to directly call these services to achieve connectivity via MODULBUS or RS232 interfaces, which is faster than using OPC； During configuration, by setting up the communication between the two sides properly, it becomes possible to view the data from the PLC; thereafter, data can be read and written using addresses (some software requires a dedicated data area for this purpose). Please provide the model of your configuration software and PLC, as well as the number of transfer points; then we may all be able to offer more suggestions. :lol :lol
http://bbs.hcbbs.com/viewthread.php?tid=209545&highlight=DCS%D3%EBPLC The introduction on the sixth floor is more detailed
It is said that DCS belongs to the category of automatic instrument control systems, while PLC falls under the electrical field. Can it be classified in this way?
This view is one-sided; DCS is a distributed control system, while PLC is a programmable controller. A PLC can be a component of a DCS.
There are MODBUS, PROFIBUS, and so on, or OPC can be used
It depends on whether the DCS can be connected directly to the PLC, communicating via Profibus or similar methods
In terms of development, DCS evolved from instruments or process control, while PLC originated from electrical equipment control; therefore, the analog signal processing in DCS is more advanced.
The moderator has already given a rating! TKS. Regarding communication: DCS systems generally use internal, proprietary networks ； For example, Hony uses LCN/UCN ； Yokogawa uses VNet. PLC will promote several networks and make them available as standards ； Such as AB’s DeviceNet, ControlNet, DH+, DF1, Siemens’ Profibus DP, PA, etc., Schneider, Modbus ； If DCS and PLC need to communicate, each case must be analyzed on a case-by-case basis ； Generally, it is possible to: 1. Add communication cards supported by PLCs to the DCS, such as Profibus, DeviceNet, or Modbus cards. 2. OPC/DDE communication is achieved through data exchange between the host computers. 3. Using a PLC as the IO for a DCS for expansion is a more complex approach, with specific solutions required for each particular case.
Generally, Modbus communication is used; both the DCS side and the PLC side need to have corresponding communication cards. It’s sufficient to define the master and slave stations, and then assign addresses!
A PLC is a small system; it can be a component of a DCS.
A PLC with an additional communication card can be connected to a DCS
The communication methods between DCS and PLC include the following: 1. MODBUS 2. Ethernet