AB 1771-OB输出模块

AB 1771-OB输出模块

a.小型PLC

I/O点总数一般小于或等于256点。其特点是体积小、结构紧凑，整个硬件融为一体，除了开关量I/O以外，还可以连接模拟量I/O以及其他各种特殊功能模块。它能执行包括逻辑运算、计时、计数、算术运算、数据处理和传送、通讯联网以及各种应用指令。如OMRON的C P/H、CPM1A系列、CPM2A系列、CQM系列，SIMENS的S7-200系列。

b.中型PLC

I/O点总数通常从256点至2048点，内存在8K以下，I/O的处理方式除了采用一般PLC通用的扫描处理方式外，还能采用直接处理方式，即在扫描用户程序的过程中，直接读输入、刷新输出。它能联接各种特殊功能模块，通讯联网功能更强，指令系统更丰富，内存容量更大，扫描速度更快。如OMRON的C200P/H，SIMENS的S7-300系列。

c.大型PLC

一般I/O点数在2048点以上的称为大型PLC。大型PLC的软、硬件功能 具有 的自诊断功能。通讯联网功能强，有各种通讯联网的模块，可以构成三级通讯网，实现工厂生产管理自动化。

a. Small PLC

The total number of I/O points is generally less than or equal to 256 points. It is characterized by small size and compact structure, and the entire hardware is integrated, in addition to the switching quantity I/O, it can also connect the analog quantity I/O and various other special function modules. It can perform logic operations, timing, counting, arithmetic operations, data processing and transmission, communication networking and various application instructions. Such as OMRON's CP /H, CPM1A series, CPM2A series, CQM series, SIMENS 'S7-200 series.

b. Medium-sized PLC

The total number of I/O points is usually from 256 points to 2048 points, the memory is below 8K, I/O processing in addition to the general PLC general scanning processing, but also can use direct processing, that is, in the process of scanning the user program, directly read the input, refresh the output. It can connect various special function modules, communication networking function is stronger, instruction system is richer, memory capacity is larger, scanning speed is faster. Such as OMRON C200P/H, SIMENS S7-300 series.

c. Large PLC

Generally I/O points above 2048 points is called a large PLC. The software and hardware functions of large PLC have self-diagnosis function. Communication networking function is strong, there are various communication networking modules, can form a three-level communication network, to achieve the automation of factory production management.