ppp | 易学教程

How can I communicate with a 3G modem via pySerial while it is connected?

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问题 I'm running Ubuntu 11.04 and a ZTE 3G modem. The modem is dialed with WvDial When the modem is not in use by WvDial I can send AT commands to the modem, and get information like signal strength: AT+ZCSQ +ZCSQ: 1, -87 OK But when WvDial is using the modem, /dev/ttyUSB0 is locked and I can't query it. Am I missing something obvious? Is there any way I can configure the modem, WvDial , or pyserial so I can send AT commands to the modem while it's connected? 回答1: Ah. Apparently this modem exposes

How can I communicate with a 3G modem via pySerial while it is connected?

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Point Patterns in Spatstat

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问题 I am having a few problems with creating a point pattern in the R package Spatstat. > HI06mfav <- read.table("MarHI06mfav.txt", header = TRUE) > attach(HI06mfav) The following object(s) are masked _by_ '.GlobalEnv': x, y The following object(s) are masked from 'HI06mfav (position 3)': x, y > HI06mfav.P <- ppp(x, y, c(-1, 11), c(-1, 11)) Warning message: In ppp(x, y, c(-1, 11), c(-1, 11)) : 10 points were rejected as lying outside the specified window > HI06mfav x y 1 4.100800 6.526913 2 3

Why LCP negotiation over PPPoS session doesn't start via LWIP, between STM32F7 and Telit GL865 GSM Modem?

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问题 I am using Telit GL865 GSM Modem with STM32F7 nucleo development board. I make them communicate via USART1. Firstly, I configure the modem with AT commands as below; after that, modem starts to send LCP packages and since I cannot handle them, NO CARRIER message occurs at the end. What I am not sure is that am I applying the right AT commands since it is different than the link I am sharing: https://github.com/espressif/esp-idf/blob/master/examples/protocols/pppos_client/main/pppos_client

重读TCP/IP（2）之链路层

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链路层属于 OSI 模型的第二层，第一层物理层主要研究的是传输媒介，电线电缆等，而第二层主要研究的是物理寻址，链路层的主要目的是为 IP 模块发送和接收 IP 数据报，为 ARP 模块发送 ARP 请求和应答，以及为 RARP 发送 RARP 请求和接收 RARP 应答，它起着承接第一层和第三层的作用，这边主要介绍当今网络上最流行的两种二层技术，以太网和 PPP 协议以太网以太网是 Xerox 公司发明的基带 LAN 标准，它采用带冲突检测的载波监听多路访问协议（ CSMA/CD ），速率为 10Mbps, 传输介质为同轴电缆，目前已经发展到 10G ，传输介质也改为光纤，以太网 2.0 之前有两种标准，一种是以太网标准，另一种是在以太网基础上完成的 IEEE802.3 定义的以太网，封装格式也有稍许不同，但是现在的以太网设备一般都兼容这两种格式以太网头部 1. 前导同步符/帧起始定界符：7字节0x55, 用于信号同步，1字节0xd5(10101011)表示一帧开始 2. 目的地址：6字节，（XX:XX:XX:XX:XX:XX） 3. 源地址： 6字节， (XX:XX:XX:XX:XX:XX) 4. 类型/长度：2字节，0~1500保留为长度域值， 1536~65535保留为类型 5. 数据：46~1500 字节 6. 帧校验序列（FCS）: 4字节，

STM32 LWIP PPPos implementation

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问题 On my STM32F7 I have to connect a 3G modem using serial port. I can communicate with the modem using AT commands. I would like to use PPPos (PPP over serial) library from LWIP to enter in PPP mode. So I take a long look at the official documentation http://lwip.wikia.com/wiki/PPP and https://github.com/tabascoeye/lwip/blob/master/doc/ppp.txt I understand the guideline but I'm really surprise there is no implementation example with serial port. Indeed, I think there is a lot of modems that

STM32 LWIP PPPos implementation

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On my STM32F7 I have to connect a 3G modem using serial port. I can communicate with the modem using AT commands. I would like to use PPPos (PPP over serial) library from LWIP to enter in PPP mode. So I take a long look at the official documentation http://lwip.wikia.com/wiki/PPP and https://github.com/tabascoeye/lwip/blob/master/doc/ppp.txt I understand the guideline but I'm really surprise there is no implementation example with serial port. Indeed, I think there is a lot of modems that have a serial interface, so I thought i can easily find an example of use. Anyone have already done that

How can I communicate with a 3G modem via pySerial while it is connected?

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I'm running Ubuntu 11.04 and a ZTE 3G modem. The modem is dialed with WvDial When the modem is not in use by WvDial I can send AT commands to the modem, and get information like signal strength: AT+ZCSQ +ZCSQ: 1, -87 OK But when WvDial is using the modem, /dev/ttyUSB0 is locked and I can't query it. Am I missing something obvious? Is there any way I can configure the modem, WvDial , or pyserial so I can send AT commands to the modem while it's connected? Ah. Apparently this modem exposes a couple of ttys to work with. I was able to use /dev/ttyUSB1 to sent AT commands while WvDial was

What uri pattern do I need to communicate with my PC from my handheld device?

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问题 As I was reminded here, I need to probably use "ppp_peer" to programmatically connect from my Compact Framework app to my Web API app running on my PC. I have tried this (replacing an IPAddress with "ppp_peer"): string uri = string.Format("http://ppp_peer:28642/api/FileTransfer/GetHHSetupUpdate?serialNum={0}&clientVersion={1}", serNum, clientVer); ...but I get, " NullReferenceException " in "Main" (prior to this I got "Unable to Connect to the Remote Server"). I have a breakpoint in the

PPP Server on Windows

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We have a solution where some hardware connects to a COM port on a Win 7 machine, and interacts with our Java app. The hardware wants to use a PPP Server to transparently connect to an other server over TCP/IP. Does anyone have a suggestion on how to do this? Start an OS native PPP Server from the Java app, with a connection to the COM port? How is this done? You may be surprised to find that Win7 still supports PPP natively. Follow these steps (or something like them) and you should be mostly good to go. I haven't actually performed a PPP connection since probably Win98, maybe Win2k, but the