共查询到20条相似文献，搜索用时 93 毫秒
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《内蒙古科技与经济》2017,(21)
文章介绍了西门子S7-400系列PLC与三菱FR-A700系列变频器通过Profibus-DP现场总线的数据通讯,主要讨论了通讯协议、变频器通讯的相关参数设置、通讯适配器FR-A7NP等,且在Step-7编程软件环境下实现S7-400PLC与三菱FR-A700变频器的实时通讯,同时给出了相关组态流程及源程序。 相似文献
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为了实现能源的充分利用,需要对电机进行转速调节,系统中由PLC完成数据的采集和对变频器、电机等设备的控制任务.本文基于FX系列PLC的编程软件,采用模块化的程序设计方法,减少软件的开发和维护。利用对PLC软件的设计,实现变频器的参数设置、故障诊断和电机的启动和停止。 相似文献
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PLC和变频器是全自动上料装置重要组成部分,整个装置的运行、停止、抓料、放料、定位等作业均由PLC和变频器及其附属控制部分完成。整套装置通过给定运行信号,经由编码器和接近开关等检测原件将信号传输给PLC,经PLC进行逻辑运算后发出指令给变频器,变频器根据PLC指令再按程序驱动电动机,由电动机驱动整套装置进行必要的作业。本文对PLC和变频器在全自动上料装置上的相关运用进行分析和研究。 相似文献
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随着电力电子技术以及自动化控制技术的发展,使得交流变频调速系统,软启动调速系统在工业电机拖动领域得到广泛应用,另外,由于PLC功能强大,容易使用,高可靠性,常常被用来作为现场数据的采集和设备的控制,本文简要分析了PLC、变频器、软启动系统的技术特点,及在煤矿领域上的典型应用,对PLC、变频器控制系统、软启动控制系统进行了探讨. 相似文献
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本文以日本富士公司G11/P11系列变频器为例，介绍串行通信技术在交流变频调速控制系统中的应用，提出利用可编程序控制器（PLC）实现串行通信编程设计方法。 相似文献
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本文主要介绍PLC在国产高压大功率变频器中的运用,并通过PLC的特殊功能模块实现高压大功率变频器的PID闭环控制. 相似文献
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在传统的变频调速恒压供水设备中,通常采用带有输入／输出模块的可编程控制器并辅以继电器电路。由于PLC功能强大,设计人员习惯于对其的过分依赖,而对变频器的使用仅仅限于交流变频调速。由于PLC在使用过程中需要设计用户程序,专业的输入输出端口等,造成用户的使用成本增高。随着电力电子技术的发展,采用带有内置PID功能和多泵控制技术的变频器,不仅降低了设备成本,还提高了生产效率。 相似文献
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随着控制技术的发展与完善,变频器及PLC在各个行业的应用愈来愈广,PLC与变频器的可靠性、灵活性得到了用户的认可。主要阐述了基于S7—200PLC和变频器控制的小区恒压供水系统的构成、工作原理和控制方式,并且编写了水泵投切运行的主要程序。 相似文献
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Emerson, regarded as one of the greatest thinkers in the American history, greatly influenced America both in literature and ideology. This thesis mainly deals with Emerson's main stream of thoughts and ideas together with his impact on the people in America in general. 相似文献
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污水处理的石灰液转槽泵(注:液下泵)是污水处理工艺流程中添加石灰液工序的一台重要设备,石灰液转槽泵的正常运转关系着污水处理的进度和排放指标的控制。保证石灰液转槽泵的正常运转,除了加强平时的维护保养外,对泵的维修质量也提出了更高的要求。作者在维修工作中不断积累经验,摸索出一套维修液下泵的拆装技巧及技术要求,进一步提高了维修质量。针对液下泵结构存在的缺陷,根据理论知识并结合实践经验,对其缺陷大胆地进行改进,有效地解决了液下泵容易出故障的问题。 相似文献
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Walls LD 《Isis; an international review devoted to the history of science and its cultural influences》2010,101(3):590-598
While literary works are often treated as museum pieces, an alternative Romantic/ Pragmatic aesthetic emphasizes instead the rootedness of all texts in lived experience. This suggests that both literary and scientific texts may be approached as performances that weave together discursive and material elements, giving language to matter, both making, and becoming, "things that talk." Three authors are contrasted: Emerson uses natural objects as metaphors to complete his thought; Thoreau uses natural objects as mediators who enroll him to speak for them in the name of a wider ecology; Humboldt attempts to enroll nonhumans, namely cannibals, into the global civil community by asking them to speak for themselves. The resulting quandary unsettles the Cartesian boundary between human and nonhuman, subject and object; as scholars divided by this boundary, we must multiply our own relations, the better to understand the ties that bind us into the common project of building the Cosmos. 相似文献
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文章提出一种智能控制加热柜热泵系统的实现方案,介绍了智能控制加热柜热泵系统的结构形式,分析了智能控制加热柜热泵系统和采用的智能控制技术,在此基础上重点阐述了智能控制加热柜热泵系统设计及GPRS计算机远程监控技术的实现。 相似文献
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抽油泵抽油是当前国内外石油开采中应用最广泛的机械采油技术,我国85％以上的油井都是采用抽油泵抽油开采的。抽油泵作为机械采油的主要设备,在油田开发生产中占重要地位,而由于抽油泵结构及特定工作环境,使得抽油泵出现各类故障。本文主要针对抽油泵上部与油杆连接部分存在的问题,设计改进了抽油泵滑杆;在现场取得了较好的效果,使抽油泵滑杆的故障率大为降低,取得了很好的经济效益。 相似文献
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Gang Li Yahui Luo Qiang Chen Lingying Liao Jianlong Zhao 《Biomicrofluidics》2012,6(1):014118-014118-16
This paper presents an easy-to-use, power-free, and modular pump for portable microfluidic applications. The pump module is a degassed particle desorption polydimethylsiloxane (PDMS) slab with an integrated mesh-shaped chamber, which can be attached on the outlet port of microfluidic device to absorb the air in the microfluidic system and then to create a negative pressure for driving fluid. Different from the existing monolithic degassed PDMS pumps that are generally restricted to limited pumping capacity and are only compatible with PDMS-based microfluidic devices, this pump can offer various possible configures of pumping power by varying the geometries of the pump or by combining different pump modules and can also be employed in any material microfluidic devices. The key advantage of this pump is that its operation only requires the user to place the degassed PDMS slab on the outlet ports of microfluidic devices. To help design pumps with a suitable pumping performance, the effect of pump module geometry on its pumping capacity is also investigated. The results indicate that the performance of the degassed PDMS pump is strongly dependent on the surface area of the pump chamber, the exposure area and the volume of the PDMS pump slab. In addition, the initial volume of air in the closed microfluidic system and the cross-linking degree of PDMS also affect the performance of the degassed PDMS pump. Finally, we demonstrated the utility of this modular pumping method by applying it to a glass-based microfluidic device and a PDMS-based protein crystallization microfluidic device. 相似文献