模块的插件板与总线底板插接不严密;
拨码开关错误;通讯线接线方向错误;
终端匹配器未接;
硬件跳线与实际信号要求的类型不一致;
机柜内系统电源、现场电源输出有误;
硬件本身坏。
以上几方面问题的结果表现为：
加电后硬件板极故障(指示灯显示状态不对);
设备不工作;
系统工作但显示的对应测点值不正确、系统的输出不能驱动现场设备等等。
4、软件报错，如何处理?
软件组态与硬件协调有误出现的问题
数据库点组态与对应通道连接的现场信号不匹配;
鼠标驱动程序加在COM1口，造成系统在线运行时不能用鼠标操作;
打印机不打印等等。
5、连线接头改注意哪些问题?
连线接头问题
连接头没有采用压焊或焊接不好造成虚焊;
热循环使接头松动;
螺栓连接点因震动引起松动;
连接点因腐蚀而接触不良。
6、电源故障改从哪些方面分析?
电源问题
电源问题分为电源连线问题和电源质量问题。
电源连线问题
包括：没有连线(火、地、零几项中，其中一项没接);错误连线(火线与零线反接，地线与零线反接，地线与零线多点短接)。
This incident was caused by two reasons: one is the excessive control of unnecessary online traffic; The second is the software vulnerability pointed out in an ISS security announcement in 1998.
Since investigators, hackers and security issues are essentially transferred from the IT field, it may be useful to find solutions from there. In the field of it (especially for personal computers), security vulnerabilities are solved by applying security patches. Unfortunately, this leads to the need to cycle multiple patches throughout the product cycle.
For example, Adobe ? Reader 9.0. For example. Between February 2008 and December 2012, Adobe released 33 important security updates for the product. That is, for a single software application, there is a patch every 7 weeks. In addition, most computers have dozens of applications even if they don't have hundreds, so ordinary it computers need to be patched at least once a week (need to be
