How to implement the M/M/1 queue model using NS3. I need it for the p2p simulation. Any reference or source code would also work. Or are there any other simulators to model M/M/1 queues?
There is no M/M/1 queue example in the ns-3 mainline, but I have written one as a course lab exercise. See section IV of Lab 1 at https://depts.washington.edu/funlab/resources/ee-595-wireless-networks-for-4g5g/. The code corresponding to this is at https://gitlab.com/tomhenderson/ns-3-ee-595 (checkout the 'course' branch).
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I'm completely new to the space and i have a project that i would like to complete, the project is basically: extracting sensor data in the form of MODBUS than sending the data out through CANBUS. i already have a mod-bus input and a can-bus output.
researching into MODBUS has been a bit confusing so sorry if these questions seem a bit stupid.
Is it possible to write code which can convert MODBUS to CANBUS? or will i need external hardware.
additionally, i'm looking to add a microprocessor to my dev board, is there anything in specific i should look for that would help with my modbus and canbus operations? or will any microprocessor work.
thank you
The basics of all data communication is the OSI model. Start there. Then you'll eventually find out that Modbus is an application layer protocol standard and CAN is a physical/data-link layer standard.
Therefore your question doesn't make any sense. You can't convert an application layer into a physical/data-link layer. You can however convert Modbus to some specific application tier protocol for CAN, such as for example CANopen, Device Net or J1939. Or a custom one.
The lowest layers underneath Modbus is UART and most likely RS-485. Possibly RS-232.
You will need a RS-485 or RS-232 transceiver between the Modbus sensor and your MCU. And you will need a CAN transceiver between your MCU and the CAN bus. Additionally, it is very strongly advised to pick a MCU with built-in CAN controller hardware.
Pick a target hardware that suits your project, don't pick some random dev board and then try to duct tape it with misc hardware to suit the project requirements.
However, the hardware is the easy part. Buying and configuring protocol stacks for whatever application protocols you are using is the hard and expensive part.
Also, there are lots of companies making gateways, so why re-invent the wheel. If you need to convert between for example Modbus and CANopen, these are both well-known industry standards. Consider just buying a gateway.
I have been playing around with OpenThead for about a month and I have set up two TI CC2538s in an OpenThread network, currently, I can send pings between them and modify the network parameters using the CLI, but they aren't capable of much else.
I would like to develop an application for them that is capable of transmitting some form of data using the OpenThread stack, maybe something simple at first like transmitting a block of text, however, I am not really sure where to start with this, are there any example applications that I could use as a starting point?
For application layers that sit directly on top of OpenThread, Nordic has released some examples in their nRF5 SDK for Thread.
Also note that Thread (and OpenThread) implement an IPv6 link capable of transporting vanilla IPv6 datagrams. As a result, you could run other transport protocols like TCP. However, UDP is often recommended due to relatively high loss rates and latency variance that is common to low-power, wireless mesh networks.
I have a computer that needs to constantly scan online information and then in accordance to what has been found, the micro controller ( assume an ardunio ) will act in a particular way.
However it seems that most micro controllers cannot be dynamically updated via USB cable. Is there a way to constantly give new instructions or commands to a previously uploaded program into the processor to make it do corresponding actions?
Thank you (I'm sorry if this isn't the right forum to post this question, but I couldn't find one for micro controllers :( )
However it seems that most micro controllers cannot be dynamically updated via USB cable
if you mean programming the microcontroller via usb then it is possible but not at all necessary. you could just send predefined instructions via USB (using LUFA for example) or UART (supported on most microcontrollers) or other data transfer protocols in order to change the state of your program on the hardware side.
if you're new to microcontrollers you should read one of many online tutorials on the subject. arduinos are specially designed for beginners and they have their own forums where you could ask questions. if you choose to go with AVR, i would recommend avrfreaks.
Use serial communications. Install a special driver found on mbed, and then also use PySerial to be able to constanly update the mbed (Any other microcontroller would work)
What is the procedure of implementing TDMA scheme on GNU radio using USRP?
I want to implement TDMA scheme using two USRPs as a transmitter and the third one as a receiver. The requirement is that first transmitter sends some data to the receiver for first 10 seconds and then after a delay of two seconds, the second transmitter sends some data to the receiver for another 10 seconds and this process continues to do so. Anyone who can help or provide with some useful links in order to implement this whole process in GNU radio software?
I am in the middle of implementing a TDMA radio. My design relies on GPS sync on the GR host platform. I use its time to sync my USRP using set_time_unknown_pps using an arg that is 2 seconds in the future.
My MAC block is purely message based, acting as a PDU broker between the application and PHY layer. PDU's to be transmitted are tagged with a tx_time command with time set an appropriate amount into the future. I've had to write several OOT blocks to handle tx_[sob,eob] tagging and other PHY details, but in the end packets come out exactly when they need to. The turn on latency for my B200mini appears to be about 1-2 us, which is fine for my timing requirements.
My advice is to start with simple MAC functions and test all the way along until you are confident with a block, then move down the transmit chain.
Anticipating your obvious question, I cannot release any of my code because it's not my code to release :-)
Here is a useful link, explaining how a TDMA system may be implemented in GNU Radio.
I want to to execute the SPI protocol operation using GPIO Pins, want to configure to single slave operation, in which way I have to configure that, I am using STM32F100RB Microcontroller and Coocox IDE for this executing in windowsxp.
if any body have example source code regarding the configuration of SPI Protocol operation using GPIO pins, then please send me that.
it very helpful for my project, Thanks in advance.
Regards,
Pavan Neo.
You're asking about Bit banging. This is the process of using an IO (or several) to encode or decode a serial signal. Wikipedia has a good description of this process.
For SPI specifically, you will need two or three outputs (depending on whether or not chip select is needed) and one input. You'll have to ensure that your bits are set or read in the correct order to not violate any setup/hold requirements of your peripheral, and you'll need to pay attention to the polarity needed on the clock signal (to make sure you're reading/writing data on the correct edge).
The Wikipedia link has some example code for bit banging that you may find useful as a starting point.