CP60-CPU CP60 CP40B-CPU CP40B   工控产品  自动化设备

CP60-CPU CP60 CP40B-CPU CP40B   工控产品  自动化设备

产品均非实价，询价请联系商家。

【主营产品】

贝利Bailey。Allen-Bradley。福克斯波罗Foxboro。

DCS  PLC  伺服系统 机器人系统 配件。Schneider施耐德。艾默生EMERSON。Woodward伍德沃德。

Westinghouse西屋。WEStation 系统备件。OVATION系统、WDPF系统、WEStation系统备件。


Honeywell霍尼韦尔。Triconex英维思。Motorola摩托罗拉。Rockwell/Reliance罗克韦尔。

ABB。XYCOM。本特利Bently。GE通用电气。Yaskawa安川。Bosch Rexroth博世力士乐。

Yokogawa横河。Siemens(西门子)。Modicon莫迪康。

In terms of database:
DCS generally provides a unified database. In DCS system, once a data exists in the database, it can be referenced in any case. The database of PLC system is usually not unified. Configuration software, monitoring software and even filing software have their own database
. In terms of time scheduling:
Generally, the program of PLC cannot run according to the preset cycle. PLC program is executed from beginning to end and then from the beginning（ Now some new PLCs have been improved, but the number of task cycles is still limited.
DCs can set the task cycle. For example, fast task, the same is sensor sampling. The change time of pressure sensor is very short, and it can use 200ms task cycle for sampling, while the lag time of temperature sensor is very large, and it can use 2S task cycle for sampling. In this way, DCs can reasonably schedule the resources of the controller.
In terms of network structure:
Generally speaking, DCS usually uses two-tier network structure, one is process level network. Most DCS use their own bus protocols, which are based on standard Huai serial port transmission protocol RS232 or RS485. The second layer is the operation level network, which adopts the network standard of moderate data throughput, fast transmission speed and convenient connection. Because the operation level network is generally arranged in the control room, the requirement of anti-interference is relatively low, and Ethernet is the best choice.
The task of PLC is relatively simple, the amount of data to be transmitted is generally not too large, so the common PLC system is a layer of network structure. Either the process level network and the operation level network are combined together, or the process level network is simplified as the internal connection between modules, and PLC will not or rarely use Ethernet. In terms of application objects:
PLC is generally used in small automatic control places, such as equipment control or a small amount of analog control and interlocking, while large-scale applications are generally DCS. Of course, this concept is not very accurate, but it's very intuitive. It's customary to call a system larger than 600 points as DCS and a system smaller than 600 points as PLC.