西门子代理商 PLC模块总代理

• 西门子代理商 PLC模块总代理
  过程映像、局部数据的大小

• 诊断缓存区的长度

• 保护级：
  程序和数据访问授权的定义

• 系统诊断：
  确定诊断信息的处理方法和范围

• 实时中断:
  设定周期

CPU 414-3 PN/DP 其它：

• PROFINET Interface

• 使用 NTP 规程对时间同步进行参数化

• 状态和错误指示灯：
  通过 LED 指示出内部和外部错误及运行状态，如运行 (RUN)、停止 (STOP)、重新启动 (Restart)、测试功能 (Test function) 等。

• 测试功能：
  可使用编程设备显示程序执行中的信号状态，不考虑用户程序而修改过程变量，读取堆栈存储器的内容，运行单独程序步骤，并禁用程序组件。

• 信息功能：
  可使用编程设备为用户提供有关存储器容量和 CPU 的工作模式，以及工作和负载存储器的当前使用率等方面的信息。

4、正确选择接地点，完善接地系统

接地的目的通常有两个，其一为了安全，其二是为了抑制干扰。完善的接地系统是PLC控制系统抗电磁干扰的重要措施之一。

系统接地方式有：浮地方式、直接接地方式和电容接地三种方式。对PLC控制系统而言，它属高速低电平控制装置，应采用直接接地方式。由于信号电缆分布电容和输入装置滤波等的影响，装置之间的信号交换频率一般都低于1MHz，所以PLC控制系统接地线采用一点接地和串联一点接地方式。集中布置的PLC系统适于并联一点接地方式，各装置的柜体中心接地点以单独的接地线引向接地极。如果装置间距较大，应采用串联一点接地方式。用一根大截面铜母线（或绝缘电缆）连接各装置的柜体中心接地点，然后将接地母线直接连接接地极。接地线采用截面大于22 mm2的铜导线，总母线使用截面大于60mm2的铜排。接地极的接地电阻小于2Ω，接地极埋在距建筑物10 ~ 15m远处(或与控制器间不大于50m)，而且PLC系统接地点必须与强电设备接地点相距10m以上。

信号源接地时，屏蔽层应在信号侧接地；不接地时，应在PLC侧接地；信号线中间有接头时，屏蔽层应牢固连接并进行绝缘处理，一定要避免多点接地；多个测点信号的屏蔽双绞线与多芯对绞总屏电缆连接时，各屏蔽层应相互连接好，并经绝缘处理。选择适当的接地处单点接点。

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具有自切断功能的PLC定时器设计举例

通过切断与驱动程序的联系而自复位的定时器，常被叫做“自切断”定时器。它们是编程者“工具箱”里一个很有用的工具。下面例子不是一个完整的实际应用，而是经选择，突出“自切断”定时器的操作。

使得电动机的实际工作负荷远小于额定负荷，大约占装机容量%~%的电动机在%~%的额定负荷下运行，运行效率过低。二是电源电压不对称或电压过低。由于三相四线制低压供电系统单相负荷的不平衡，使得电动机的三相电压不对称，电机产生负序转矩，增大电机的三相电压不对称，电机产生负序转矩，增大电机运行中的损耗。

应用

CPU 416-2, CPU 416-3 and CPU 416-3 PN/DP are powerful SIMATIC S7-400 CPUs.

The integrated PROFIBUS DP interfaces in the CPU 416-2 and CPU 416-3 make it possible to connect directly to the PROFIBUS DP fieldbus as a master or slave.

An additional DP master system can be connected to the CPU 416-3 and CPU 416-3 PN/DP using the IF 964-DP interface module.

The integrated PROFINET interface of the CPU 416-3 PN/DP includes switch functionality when the ERTEC 400-ASIC is used. This forms the basis for providing two externally accessible PROFINET ports. In addition to hierarchical network topologies, this also enables the creation of line structures in the new S7-400 controllers.

Note:
Only the 6ES7 964-2AA04-0AB0 interface submodule may be used.

设计

Both CPUs are equipped with the following:

• Powerful processor:
  The CPUs achieve instruction execution times as low as 0.03 µs per binary instruction.

• CPU 416-2: 5.6 MB RAM (of which 2.8 MB each for program and data);
  CPU 416-3: 11.2 MB RAM (of which 5.6 MB each for program and data);
  CPU 416-3 PN/DP: 11.2 MB RAM (of which 5.6 MB each for program and data);
  fast RAM for parts of the user program relevant to execution.

• Flexible expansion:
  Up to 262144 digital and 16384 analog inputs/outputs.

• Multi-point interface MPI:
  With the MPI it is possible to establish simple networking of max. 32 stations at a data transmission rate of up to 12 Mbit/s. The CPUs can establish up to 44 connections to stations of the communications bus (C bus) and the MPI.

• Mode selector switch:
  Designed as toggle switch.

• Diagnostics buffer:
  The last 120 fault and interrupt events are retained in a ring buffer for diagnostic purposes. The number of entries can be parameterized.

• Real-time clock:
  The date and time are appended to diagnostic messages of the CPU.

• Memory card:
  For expansion of the integrated load memory. RAM and FEPROM cards (FEPROM for retentive storage) are available

• Combined MPI/DP interface and integrated PROFIBUS DP interface (CPU 416-2 and CPU 416-3):
  The PROFIBUS DP master interface allows a distributed automation configuration offering high speed and ease of use. From the user's point of view, the distributed I/O is treated as central I/O (same configuring, addressing and programming).
  Mixed configuration: SIMATIC S5 and SIMATIC S7 as PROFIBUS master according to EN 50170.

CPU 416-3 and CPU 416-3 PN/DP also include:

• A module slot:
  An additional PROFIBUS DP master system can be connected via the IF 964-DP interface module.

CPU 416-3 PN/DP additionally includes:

• PROFINET interface with 2 ports (switch):

• PROFINET I/O, 256 IO devices connectable

• PROFINET CBA

功能

• Block protection:
  A password concept protects the user program from unauthorized access.

• Integral HMI services:
  The user only has to specify the source and destination of the data with HMI devices. The data are then transported cyclically and automatically by the system.

• Integrated communications functions:

• PG/OP communication

• Shared data communication

• S7 standard communication

• S7 communication

• Firmware update using network

CPU 416-3 PN/DP additional:

• Open communication over TCP/IP, UDP and ISO-on-TCP (RFC1006)

• Distributed intelligence in Component Based Automation (CBA) on PROFINET

• Additional diagnostic options with integrated web server

The STEP 7 tool "Hardware Configuration" can be used to program the properties and response of the S7-400 including the CPUs, e.g.

• Multi-point interface MPI:

• Definition of station addresses.

• Startup/cycle behavior

• Stipulation of the maximum cycle time and communications load

• Address assignment:
  Addressing of I/O modules.

• Retentive ranges:
  Definition of the number of retentive bit memories, counters, timers, data blocks and clock memories.

• Size of the process image, local data.

• Length of the diagnostics buffer

• Protection level:
  Definition of access authorization for program and data

• System diagnostics:
  Definition of the handling and scope of diagnostic messages

• Timed interrupts:
  Setting of periodicity

CPU 416-3 PN/DP additional:

• PROFINET interface

• Parameterization of time synchronization using NTP procedure

• Status and error indicators:
  LEDs indicate internal and external errors and operating states such as RUN, STOP, Restart, Test function, for example

• Test functions:
  The programming device can be used to display signal states in program execution, modify process tags irrespective of the user program, read out the contents of stack memories, run separate program steps and inhibit program components

• Information functions:
  The programming device can be used to provide the user with information on the memory capacity and operating mode of the CPU and the current utilization of the working and load memories

• 西门子代理商 PLC模块总代理