产品详情
AO810 3BSE008522R1 ABB模拟输出模块 工控备件
预计交货时间:3-5天
制造商:ABB
产品订货号：3BSE008522R1
产品类型:模拟输出模块
产品ID: 3BSE008522R1
ABB型号:AO810
目录描述:AO810模拟输出1×8 ch，
模拟输出1×8 ch
运输重量:0.8kg
AO810V2 3BSE038415R1
购买咨询热线:18059884797 （微信同号）
QQ：3095989363
邮箱：sales@xiongbagk,cn
地 址：福建省漳州开发区南滨大道429号招商局芯云谷3号楼217-01
公司：厦门雄霸电子商务有限公司漳州分公司
Reasonable selection of PLC, to improve the application of PLC in the control system has an important role. In this paper, PLC models, I/O, memory type and capacity and programming device, external equipment to illustrate the selection of PLC should be considered factors, and gives two examples of PLC application. In this paper, although some methods of selecting PLC are summarized, appropriate adjustments must be made according to the actual situation in the actual work, so as to design the industrial control system to meet the expectations.
With the popularization of PLC in industrial control, more and more kinds of PLC products, its structure model, performance, capacity, instruction system, programming methods are different, applicable occasions also have their own emphasis. Therefore, the reasonable choice of PLC, to improve the application of PLC in the control system has an important role.
First, the selection of models
The following PLC products are popular in our market:
1. Schneider Company, including the early introduction of Modicon products in Tianjin Instrument Factory, now there are Quantum, Premium, Momentum and other products;
2. Rockwell PLC products (including AB), currently SLC, Micro Logix, Control Logix and other products;
3. Siemens products, currently have SI*TIC S7-400/300/200 series products;
4. GE products;
5. Japanese Omron, Mitsubishi, Fuji, Panasonic and other company products, which are used more Mitsubishi F1, F2, FX2 series products.
The basic principle of PLC model selection is: on the premise that the function meets the requirements, select the most reliable, convenient maintenance and use, as well as the best performance and price ratio model. Usually do the most energetic development; In addition, because of its general external equipment, resources can be shared, therefore, with the above computer can control the independent system of multiple PLC into a DCS system, so easy to communicate with each other, centralized management.
Second, I/O selection
PLC in the 1990s has formed a variety of micro, small, medium, large, giant PLC. According to I/O points, can be divided into micro PLC (32I/O), small PLC (256I/O), medium-sized PLC (1024I/O), large PLC (4.69I/O), giant PLC (8195I/O) five.
The connection between PLC and industrial production process is realized through I/O interface module. PLC has many I/O interface modules, including switch input module, switch output module, analog input module, analog output module and some other special modules, use should be selected according to their characteristics.
(I) Determine the number of I/O points
When the required I/O points are determined according to the requirements of the control system, 10% ~ 20% of the spare amount should be added to increase the control function at any time. For a control object, the number of I/O points should be different due to different control methods or different programming levels. Table 2 lists the I/O points required for switching quantities for typical transmission equipment and common electrical components. (2) Switching quantity I/O
Switching capacity The I/O interface receives signals from sensors and switches (such as buttons, limit switches, etc.) and control devices (such as indicators, alarms, motor starters, etc.). The typical ac input/output signal ranges from 24 v to 240V, and the dc input/output signal ranges from 5 v to 240V. Although the input circuit VARIES from manufacturer to MANUFACTURER, some features are common, such as the jitter circuit used to eliminate error signals. In addition, most input circuits have an optional isolation circuit between the HV power input and the control logic portion of the interface circuit. When evaluating discrete outputs, consider fuses, instantaneous surge protection, and isolation circuits between power and logic circuits. A fuse circuit may cost more initially, but it may cost less than an external fuse.
(3) Analog I/O
Analog input/output interfaces are generally used to sense signals generated by sensors. These interfaces can be used to measure flow, temperature, and pressure, and can be used to control voltage or current output devices. Typical ranges for these interfaces are -10 to +10V, 0 to +11V, 4 to 20*, or 10 to 50*. Some manufacturers design special analog interfaces on PLC, so it can receive low level signals, such as RTD, thermocouple, etc. In general, this type of interface module can be used to receive mixed signals of different types of thermocouple or RTD on the same module.
(4) Special function I/O
When selecting a PLC, the user may be faced with some special types of I/O restrictions that cannot be implemented with standard I/O (such as positioning, fast input, frequency, etc.). At this time, the user should check whether the manufacturer provides special modules that help minimize the control effect. Some special interface modules can process part of the field data by themselves, thus freeing the CPU from heavy tasks.
(5) Intelligent I/O
At present, PLC manufacturers have launched a number of intelligent I/O modules. General intelligent type I/O module itself with a processor, the input or output signals for pre-specified processing, and the processing results into the CPU or direct output, so can improve the processing speed of PLC and save the capacity of memory. 3. Selection of memory type and capacity
The memory used by the PLC system is basically composed of PROM, EPROM and RAM three types. The storage capacity varies with the size of the machine. The maximum storage capacity of the general minicomputer is less than 6kB, the maximum storage capacity of the medium-sized machine is up to kB, and the maximum storage capacity of the mainframe can be up to megabytes. When used, suitable models can be selected according to the needs of program and data storage, and the expansion of memory can be specially designed when necessary.
PLC memory capacity selection and calculation of the first method is: according to the number of nodes used by programming to calculate the actual use of memory capacity. The second method is estimation method. Users can estimate according to the formula in Table 4 according to the control scale and application purpose. In order to be easy to use, generally should leave a margin of 25% ~ 30%, the best way to obtain storage capacity is to generate the program, that is, how many words. Knowing the number of words per instruction, the user can determine the exact memory capacity. Table 4 also shows the estimation method of memory capacity. Four, the choice of programmer and external equipment
In the process of system implementation, PLC programming is very important. The user should have an understanding of the software function and programmer of the selected PLC product. Under normal circumstances, small control systems generally choose cheap simple programmer, if the system is large or multiple PLC sharing, you can choose strong function, programming convenient graphic programmer. If you have a personal computer, you can choose a programming package that will run on your personal computer. At the same time, in order to prevent the user program in RAM from being destroyed due to the voltage drop of * and lithium batteries, the EEP-ROM module can be selected as an external device.
