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CPU22X 主机的输人点为 24V 直流双向光藕合输人电路，输出有继电器和直流 ( Mos 型）两种类型。
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相关试题
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高速计数器可以用于捕捉比 CPU 扫描频率更快的脉冲信号。
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cPU22x 主机的输人点有继电器和直流（ MOS 型）两种类型。
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PLc 内部元素的触点和线圈的连接是由程序来实现的。
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主机箱体外部的 RS 一 485 通信接口，用以连接编程器（手持式或 PC ）。
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模拟电位器用来改变特殊寄存器（SM28,SM29）中的数值，以改变程序运行时的参数。
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cPu 在 sToP 工作方式下， PLc 按照自己的工作方式运行用户程序。
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在程序编辑、上传、下载等处理过程中，必须把 CPU 置于 sTOP 方式。
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标有 SF 的指示灯亮时表示系统故障， PLC 停止工作。
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把方式开切到 sTOP 工作方式下，允许盯STEP7- Micro / WIN32 软件设置 CPU 工作状态。
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如果工作方式开关设为 STOP、电源上电时， CPU 自动进人 sTOP 工作状态。
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在程序中插人一个 sTOP 指令， CPU 可由 RUN 方式进人 STOP 工作方式。
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扩展模块的数量受基本单元能带扩展模块的数量和电源承受扩展模块消耗 DC5V 总线电流的能力约束。
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可编程序控制器的编址就是对 PLC 地识别元件进行编码，以便程序执行时可以唯一地识别每个原件。
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输出继电器是 PLC 用来接收用户设备输人信号的接口。
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计数器用于累计计数输人端接收到的由断开到接通的脉冲个数。
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梯形图程序设计语言（ LAD ）是最常用的一种程序设计语言。
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定时器不同的时基标准，定时精度、定时范围和定时器刷新的方式不同。
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lms 定时器每隔 1 ms 刷新一次与扫描周期和程序处理无关即采用中断刷新方式。
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, TOF 是记忆型通电延时定时器指令。
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循环移位将移位数据存储单元的首尾相连，同时又与溢出标志 sM1、1 连接， SM1.1 用来存放被移出的位。
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在 SCR 段中能使用 JMP 和 LBL 指令。
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程序应按自上而下，从左至右的顺序编写。
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良好的接地是抑制噪声干扰和电压冲击保证 PLC 可靠工作的重要条件。
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可编程序控制器具有很完善的自诊断功能可以不要保护电路。
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开环数控机床通常指的是未安装反馈装置的数控机床。
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数控机床所用的功率步进电动机带有光电编码器。
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常用的位移执行机构有步进电动机、直流伺服电动机和交流伺服电动机。
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半闭环控制数控机床的检测装置安装在丝杠或电机轴上，闭环控制数控机床的测量装置安装在工作台上。
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应用网关是在应用层实现网络互联的设备。
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目前使用的广域网基本都采用网状拓扑结构。
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通常互联网所采用的 TCP / IP 协议中的 TCP （传输控制协议）协议就是属于运输层。
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PRoFIBUS 现场总线最多可挂接 127 个站点。
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1、RS-485 传输速率 9.6KB/s ~ 12MB/s 。
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PROnBUS 总线存取协议，主站之间采用主从方式，主站与从站之间采用令牌传送方式。
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电场屏蔽主要靠屏蔽体壳体上感生的涡流所产生的反磁场起排斥原磁场的作用。
推荐试题
【单选题】
Which feature can help a router or switch maintain packet forwarding and protocol states despite an attack or heavy traffic load on the router or switch？___
A. service Policy
B. Control Plane Policing
C. Policy Map
D. Cisco
E. xpress
F. orwarding
【单选题】
Which STP feature can prevent an attacker from becoming the root bridge by immediately shutting down the interface when it receives a BPDU？___
A. root guard
B. Port Fast
C. BPDU guard
D. BPDU filtering
【单选题】
Which technology can best protect data at rest on a user system？___
A. full-disk encryption
B. IPsec tunnel
C. router ACL
D. network IPS
【多选题】
Which two primary security concerns can you mitigate with a BYOD solution ？___
A. schedule for patching the device
B. securing access to a trusted corporate network
C. compliance with applicable policies
D. connections to public Wi-Fi networks
E. device tagging and invento
【多选题】
choose five___
A. MD5————————inserure
B. DES————————insercure
C. SDES———————legacy
D. SHA-1———————legacy
E. HMAC-MD5—————legacy
【多选题】
Which two characteristics of symmetric encryption are true？___
A. It uses digital certificates
B. It requires more resources than asymmetric ancryption
C. It uses the same key to enctypt and decrupt traffic
D. It uses a public key and a pricate key to encrypt and decrypt traffic.
E. It is faster than asymmetric encryption
【多选题】
which two characteristics of PVLAN are true？___
A. Promiscuous porta can communicate with PVLAN ports.
B. Isolated ports cannot communicate with other ports on the same VLAN
C. Community ports have to be a part of the trunk.
D. They require VTP to be enabled in server mode
E. PVLAN ports can be configured as Ether Channel ports
【多选题】
What are two options for running Cisco SDM?___
A. Running SDM from a mobile device
B. Running SDM from within CiscoWorks
C. Running SDM from a router's flash
D. Running SDM from the Cisco web porta
E. Running SDM from a PC
【多选题】
Which two options are the primary deployment modeles for mobile device management？___
A. multisite
B. cloud-based
C. on premises
D. hybrid cloud basedo
E. single site
【多选题】
Drag the recommendation on the left to the Cryptographic algorithms on the right， Options will be used more than once.___
A. Avoid——————————————DES，MD5
B. Legacy——————————————SDES，SHA1，HMAC-MD5
【多选题】
Which two are valid types of vLans using PVLANS ?___
A. Community VLAN
B. Backup VLAN
C. Secondary VLAN
D. Isolated VLAN
E. Isolated VLAN
【多选题】
Which two commands are used to implement Resilient lOS Configuration ___
A. Secure boot-config
B. copy running-config tftp
C. copy flash:ios bin tftp
D. copy running-config startup-config
E. secure boot-image
【多选题】
Which two types of firewalls work at layer 4 and above ？___
A. Stateful inspection
B. Network Address Translation
C. Circuit-Level gateway
D. Static packet filter
E. Application Level firewall
【多选题】
Which two default settings for port security are true ？___
A. Violation is Protect
B. Violation is Restrict
C. Violation is Shutdown
D. Maximum number of MAC addresses is 2
E. Maximum number of MAC addresses is 1
【多选题】
Which two are characteristics of RADIUS？___
A. Uses UDP ports 1812 /1813
B. Uses TCP port 49
C. Uses UDP port 49
D.
E. ncrypts only the password between user and server
【多选题】
When setting up a site-to-site VPN with PSK authentication on a Cisco router， which two elements must be configured under crypto map？___
A. pfs
B. nat
C. reverse route
D. peer
E. transform-set
【多选题】
When using the Adaptive Security Device Manager（ASDM), which two options are available to add a new root certificate？___
A. Install from SFTP server
B. Usehttps
C. Install from a file
D. Use LDAP
E. Use SCEP
【多选题】
Which two SNMPv3 services support its capabilities as a secure networ k manage protocol？ ___
A. access control
B. the shared secret key
C. authentication
D. authorization
E. accounting
【多选题】
Which two statements about routed firewall mode are true ？___
A. The firewall acts as a routed hop in the network
B. This mode conceals the presence of the firewall
C. The firewall requires a unique iP address for each interface
D. This mode allows the firewall to be added to an existing networ k with minimal additional configuration By default， this mode permits most traffic to pass throug
【多选题】
Which two statements describe DHCP spoofing attacks？___
A. They are used to perform man-in- the-middle attacks
B. They can access most network devices
C. They can modify the flow of traffic in transit. LNGKAIG
D. They protect the identity of ti attacker by masking the DHCP address
E. They can physically modify the network gateway
【多选题】
Which two types of VLANs using PVLANs are valid？___
A. isolated
B. promiscuous
C. backup
D. secondary
E. community
【多选题】
What are two limitations of the self-zone policies on a zone-based firewall？___
A. They are unable to block Https traffic
B. They restrict SNMP traffic.
C. They are unable to support Https traffic
D. They are unable to implement application inspection
E. They are unable to perform rate limiting
【多选题】
Which two descriptions of TACACS+ are true？ ___
A. The TACACS+ header is unencrypted
B. It combines a uthentication and authorization
C. It uses TCP as its transport protocol
D. Only the password is encrypted.
E. It uses UDP as its transport protocol.
【多选题】
Which two actions does an IPS perform？ ___
A. it spans the traffic
B. it reflects the traffic back to the sender
C. it encrypts the traffic
D. it terminates the user session or connection of the attacker
E. it reconfigures a device to block the traffic
【多选题】
In which form of fraud does an attacker try to learn information such as login credenti account information by ma squerading as a reputable entity or person in email， IM or communication channels ?___
A. phishing
B. Smurfit
C. Hacking
D. Identity Spoofing
【多选题】
Which two ESA services are available for incoming and outgoing mails ？___
A. anti-DoS
B. reputation filter
C. antispam
D. content filter
E. DLP
【多选题】
What are two reasons to recommend SNMPv 3 over SNMPv2？___
A. SNMPv3 is secure because you can configure authe ntication and privacy
B. SNMPv3 is insecure because it send in formation in clear text
C. SNMPv2 is insecure because it send information in clear text
D. SNMPv3 is a Cisco proprietary protocol
E. SNMPv2 is secure because you can configure authentication and privacy
【多选题】
Which two actions can a zone- based firewall apply to a packet as it transits a zone pair？___
A. drop
B. inspect
C. queue
D. quarantine
【单选题】
Which security principle has been violated if data is altered in an unauthorized manner？___
A. accountability
B. confidentiality
C. availability
D. integrity
【单选题】
Which IKE Phase 1 parameter can you use to require the site-to-site VPN to use a pre-shared ？___
A. encryption
B. authentication
C. group
【单选题】
Which command successfully creates an administrative user with a password of "cisco"on a Cisco router?___
A. username Operator privilege 7 password cisco
B. username Operator privilege 1 password cisco
C. username Operator privilege 15 password cisco
D. username Operator password cisco privilege 15
【单选题】
Which EAP method authenticates a client against Active Directory without the use of client-side 802.1X certificates？___
A. EAP-TLS
B. EAP-MSCHAPv2
C. EAP-PEAP
D.
E. AP-GTC
【单选题】
What is a limitation of network-based IPS？___
A. It must be in dividually configured to support every operating system on the network.
B. It is most effective at the in dividual host level
C. It is unable to monitor attacks across the entire netw ork
D. Large installations require numerous sensors to fully protect the network
【单选题】
When would you configure the ip dhcp snooping trust command on a sw itch？___
A. when the switch is connected to a DHCP server
B. when the switch is working in an edge capacit
C. when the switch is connected to a client system
D. when the switch is serving as an aggregator
【单选题】
How does the 802. 1x supplicant communicate with the authentication server？___
A. The supplicant creates EAP packets and sends them to the authenticator, which encapsulates them into RADIUS and forwards them to the authentication server.
B. The supplicant creates RADIUS packets and sends them to the authe nticator, which encapsulates the m into EAP and forwards them to the a uthentication server.
C. The supplicant creates RADIUS packets and sends them to the authenticator, which translates them into eap and forwards them to the a ut hentication server
D. The supplicant creates
E. AP packets and sends them to the authe nticator, which translates them into radius and forwards them to the authentication server.
【单选题】
Which command do you enter to verify the phase I status of a VPN connection？___
A. sh crypto se ssion
B. debug crypto isakmp
C. sh crypto isakmp sa
D. sh crypto ipsec sa
【单选题】
Refer to the exhibit. what is the e ffect of the given configuration？___
A. It enables authentication，
B. It prevents keychain authentication.
C. The two routers receive normal updates from one another.
D. The two device s are able to pass the message digest to one another.
【单选题】
Which command can you enter to configure OSPF to use hashing to authenticate routing updates？___
A. ip ospf aut hentication message-digest
B. neighbor 192 168.0 112 cost md5
C. ip ospf priority 1
D. ip ospf aut hentication-key
【单选题】
Which command can you enter to verify the status of Cisco lOS Resilient Configuration on a Cisco router?___
A. show secure bootset
B. secure boot-image
C. show binary file
D. ure boot-config
【单选题】
A user on your network inadvertently activates a botnet program that was received as an emai attachment. Which type of mechanism does Cisco Firepower use to detect and block only the botnet attack？___
A. network-based access control rule
B. reputation-based
C. user-ba sed access control rule
D. botnet traffic filter
