If you need our products, please contact us in advance------------同系列同品牌更多产品请留言喔。

             ------------我们及时为您服务！！

选择长欣的理由：

【深圳长欣自动化设备有限公司】经过十二年的快速发展，现已成为国内zui 具实力的工控备件商之一

产品应用于：电力、石油、矿井提升、港口、供热、燃气、供水、污水处理、冶金、造纸、纺织、化工、水利等现代化工业领域！

现场仪表设备包括与生产过程直接联系的各种变送器、各种开关、执行机构、负载及各种温度的一此元件等。现场仪表若发生故障，直接影响DCS系统的控制功能及操作人员对工艺参数的监视，从而给工艺操作带来一定困难。在目前的DCS控制系统设计中，这类故障占绝大部份，这类故障一般是由于仪表设备本身的质量和寿命所致。对这类故障比较直观，在判断和处理上也相对容易，在处理按常规仪表的处理方法一般不会有什么问题。对这类故障的处理要求维护人员对常规仪表的故障处理比较熟练，以***故障处理的及时性及准确性。由于这类故障属于单点故障，对工艺影响不大，维护人员对DCS系统知识的要求不高，只须按常规仪表处理即可。

系统故障： 

这是影响系统运行的全局性故障，系统故障可分为固定性故障和偶然性故障。如果系统发生故障后可重新启动使系统恢复正常则可认为是偶然性故障。相反若重新启动后不能恢复正常而需要更换硬件或软件系统才能恢复则认为是固定性故障。这种故障一般是由于系统设计不当或系统运行年限较长所致。

硬件故障： 

这类故障主要指DCS系统中（I/O模块）损坏造成的故障。这类故障一般比较明显且影响也是局部的，它们主是由于使用不当或使用时间较长，模块内元件老化所致。

软件故障： 

这类故障是软件本身所包含的错误所引起的。软件故障又分为系统软件故障和应用软件故障。系统软件是DCS系统所带来的，若设计考虑不周，在执行中一但条件满足就会引发故障，造成停机或死机等现象。此类故障并不常见，应用软件是用户自己编定的，在实际工程应用中，由于应用软件工作复杂，工作量大，因此应用软件错误几乎难以避免，这就要求在DCS系统调试及试运行中十分认真、仔细，及时发现并解决。

型号：

ABB(S800系列）

英维思(3008, 3625, 3508E. 3721, 3700A 4351B)

本特利(3500/42M， 3500/ 22M, 3500/95.3500/05)

黑马(F3330, F3236, F6217, F7126, F8621A)

福克斯波罗(FBM203, FBM204, FBM217, FMB231)

AB: (1746 1747 1756 1770 1771 1785 触摸屏2711系列CPU PLC) .

普罗索芙特PROSOFT MVI46/56/69, AB旗下，跟AB很像,模块

横河YOKOGAWA AAI, ADV, ADI, ANB, AMM, SB, PW(型号开头),卡件模块(CPU,电源,输出，PLC)

摩尔MOORE Q开头, 3开头模块,显示器

There is a program counter in the CPU of the PLC that indicates the storage address of the program step. During the program running, the counter will automatically increase by 1 after executing one step. The program will be executed from the starting step (the step number is zero) to the final step (usually the end instruction), and then return to the starting step for cyclic operation. The time required for PLC to complete each cycle operation is called a scanning cycle. For different types of PLC, the cycle scanning period is between 1 microsecond and tens of microseconds. The loop operation such as program counter is not available in DCS. This is also the reason why the redundancy of PLC is not as good as that of DCS.

DCS is developed on the basis of operational amplifier. The relationships between all functions and process variables are made into functional blocks (some DCS systems are called expansion blocks). The main difference between DCs and PLC is in the logic calculation of switching value and the operation of analog value. Even though the two later infiltrated each other, they were still different.

Since the 1980s, in addition to logic operation, the algorithm function of PLC control loop has been greatly enhanced. However, PLC is programmed with ladder diagram, and the operation of analog quantity is not very intuitive during programming, which is troublesome. However, in terms of solving logic, it shows the advantage of being fast. At the microsecond level, it can solve 1K logic program in less than 1 millisecond. It treats all inputs as switching values, and 16 bits (also 32 bits) are an analog value.

DCS regards all inputs as analog values, and 1 bit is the switching value. Solving a logic is on the order of hundreds of microseconds to milliseconds. For PLC, a PID calculation takes tens of milliseconds, which is about the same as that of DCS.

In terms of grounding resistance, the requirement for PLC may not be high, but it must be less than several ohms (usually less than 4 ohms) for DCS. Analog ***lation is also very important.

For systems with the same I / O points, the cost of using PLC is lower than that of using DCS (about 40% can be saved). PLC has no special operation station, and its software and hardware are universal, so the maintenance cost is much lower than DCS. If the controlled object is mainly equipment interlocking and there are relatively few loops, PLC is more suitable.

Our Advantage

ICS Triplex T8461,ICS Triplex T8311,ICS Triplex T8431,ICS Trusted Triplex T8310
All Yokogawa CP401-10,SCP461-51,Yokogawa CP451-10,ALR121-S50 Are Availabe
We Also Sell Emerson DeltaV EPRO Yokogawa Products,Call US Now

ENTERASYS A4H124-24TX 
Rexroth SYHNC100-NIB-2X/W-24-P-D-E23-A012
Rexroth VTS0234-47/AP025
Rexroth VT-MVTW-1-16/D   
Rexroth SYHNC100-NIB-23/W-24-P-D-E23-A012 
TRICONEX TCM 4355X 
TRICONEX MP3009X/TCM 4355X 
ABB 07AC91 GJR5252300R0101 
EMERSON VE3008 12P3439X012 KJ2003X1-BB1 
MAN B&W 3171197-4 
ABB FPR3346501R1012 
BENTLY 3500/33-01-01
BENTLY 149986-01 
ABB DSDX452L 
BENTLY 3500/62-04-02 
ABB ETP90H-4G50 
GE 469-P5-LO-A20-E
MSPC MSPC-6886/6800 
NI PCI-5421 
ABB 3BSE004258R1