Questions tagged [canopen]

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Can a CANopen node receive the SDO block upload between another pair of nodes?

I know that with PDO there can be more than one receiver, but I wonder if that also applies to SDO block upload, so if I can have node A acting as a client, node B as a server and having some "...
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Which node-ID goes into the COB-ID?

I understand (or so I think) that: CAN frames have a unique COB-ID made up of a function code plus a node ID Transmitting nodes will have a (T)PDO mapped to a COB-ID in the OD (1800h - 19FFh) ...
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Is this possible in CANopen?

I'm planning a CANopen network with a few nodes (8-9) so I'm thinking of the Node-ID using 4 bits, and 7 for the rest of the COB-ID to indicate more than the 4 basic PDOs there seems to be (as up to ...
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How to use CANopen with more than 4 PDOs?

I'm new to CANopen so excuse me if it's all nonsense. i need to specify some systems on a CAN bus network with CANopen. Because there are only 4 pre-defined PDOs and in some cases there are more data ...
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Best approach to program a PLC using dbc file? (CAN communication)

I'm pretty new using CAN Communication but I need to program a Phoenix Contact PLC in Structured Text. The PLC should communicate with a motor that uses CANOpen protocol. The only resource I have is ...
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Home automation using CAN bus

I am planning to make a prototype for wired home automation devices, and I am thinking of using CAN bus for communication between nodes and Gateway. The way I am planning to build it, there is one ...
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Different CAN-BUS specs on the same bus

I have several questions about different combinations of CAN-Bus nodes that are able to work together with realiability: CAN2.0A and CAN2.0B nodes can work on the same bus at the SAME speed? CAN2.0A ...
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Multiple CANOpen SDO requests "in the air" at once

In CANOpen, expedited SDO requests and responses include the index and sub-index of the request. All CANOpen master implementations that I've looked at require only one SDO per device be sent at once, ...
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Transmit and receive in PDO for CANopen - Why use transmit channel?

According to CiA 301, there is something called TPDO Mapping and TPDO Communication. TPDO communication is used for describing ...
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3 answers
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Process Data Objects - CANopen - How do they work?

I'm searching for information about PDO and the protocol CiA 301 V4.2.0 at topic 7.2.2.5.1 does not exactly show how PDO's work. ...
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When should I use normal SDO transfer in CANopen?

CANopen have two types of methods for transferring and receiving data between server and client. Expedited mode = Send fixed bytes (maximum 4 bytes) Normal mode = Send maximum 7 bytes at the time If ...
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Peer to Peer in CANopen - How does it work?

CANopen have something called an 11 bit COB-ID, it contains function code of 4 bits + node ID of 7 bits. For example: Image from here. Does this mean if the MASTER send a request to the CLIENT for ...
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Why are NMT masters acting as SDO clients and not SDO masters in CANopen?

According to CSSeletronics. What is the SDO service? The SDO service allows a CANopen node to read/edit values of another node's object dictionary over the CAN network. As mentioned under '...
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Where can I save the Node ID in the Object Dictionary - CANopen

I'm building a library called Easy CANopen and it will focus on embedded systems due to the portability. Language C. But storing the Node ID in the Object Dictionary can be done, but I don't know if ...
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What is the TIME frame in CANopen?

I'm looking for the TIME frame in CANopen and all I know is that: The COB ID must be 256 and The data must be 6 bytes long. But I don't know where the LSB begins ...
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What does Reset Node and Reset Communcation do in CANopen?

According to NI, NTM commands can be sent to the Node. They are the follwing: Start Remote Node Stop Remote Node Enter Pre-Operational Reset Node Reset Communication. Start Remote Node enables all ...
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Does the slave respond to the master if the master send the command specifier 0x4 or 0x15 - CANopen

According to Hydac HAT 1000, if you send with the command specifier(CS) to the slave, for example 0x4 or 0x15, then the slave will not respond back. But for other command specifiers, then the slave ...
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Sending raw data with CANopen - Which function/COB should I use then?

I want to send raw data with CANopen. Which COB-ID should I use then? My goal is to transmit for example an array of X bytes and when the receiver got that array, it going to understand how to ...
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Modbus Vs CANopen - Which one should I choose?

Modbus Vs CANopen - Which one should I choose if I want: Broadcast to all units Talk to specific units Robust Send lots of data Implement for embedded systems Easy to use Using in new projects with ...
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CANOpen Mapping Parameter Size Bits

I am working with an inclinometer. Currently 0x1A01sub1 has a value of 0x60100010. So... This means PDO2 is going to send 16 (0x10) bits of object 6010sub0. 6010sub0 is the X axis slope which is a ...
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is it possible to make cnc without embedded motion controller over CANopen [duplicate]

I want to make CNC software. while doing this, I do not want to use any motion controller, PLC, FPGA, etc... I use three items. 1-USB to CAN converter, 2-servo motors, and their drivers, 3-a computer. ...
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-1 votes
3 answers
145 views

Can a computer control up to 10 motor drivers directly via the CANopen communication protocol? [closed]

I guess my question was not so clear, so I am editing now. I want to make CNC software. while doing this, I do not want to use any motion controller, PLC, FPGA, etc... I use three items. 1-USB to CAN ...
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Encoding node ID

I am looking for a best way to encode CANOpen node ID on the PCB. At the moment it is hardcoded in the firmware. The requirements are 1) 8 or 16 values, 2) small footprint, and 3) low cost. Note that ...
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How can 3.3v CAN-bus transceiver communicate with 5 volt CAN-bus transceiver?

I'm suing TCAN33x from Texas Instruments and it's a 3.3v CAN-bus tranciever. I have succeed to listen for CAN-bus messages from a 24V J1939 CAN-bus stepper motor. Very industrial. But I haven't ...
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1 vote
1 answer
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CANopen - explanation of TPDO and RPDO

I am working on a project that uses the CANopen protocol. I have a problem with understanding the use of TPDO and RPDO. In some articles, RPDO is described as a request calling TPDO from another node, ...
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3 answers
183 views

M8 connectors and their coding

A quick read on the internet shows that M8 connectors are coded. The little info online I can find says A-coded is the most common style, typically used for sensors and actuators. B-coded is is mostly ...
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1 vote
1 answer
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Reading multiple CANbus outputs with one controller

my encoder has a CAN communication interface. I need 4 encoders for my application. However, my controller only has 1 CAN communication interface. Assuming, the encoder has different CAN ID, will it ...
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1 answer
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Power Supply issues with CAN bus

I am currently working on a system using C# for a windows GUI with an Ixxat USB-to-CAN and an STM32F303K8 that runs CANopen, The system itself is running fine I can send and receive messages to and ...
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1 answer
197 views

PCB layout for CAN bus transceiver

I have a PCBA where the connector for the CAN bus is about 40 mm away from the MCU. The MCU and connector positions are fixed but I am free in placing the CAN transceiver. I haven't worked with CAN ...
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1 vote
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CAN Open PDO mapping

I am new to CANopen protocol and could anyone help me with the difference between PDO2 and PDO3.I am receiving CAN data from the sensor and i could see the message type as TXPDO2, TXPDO3 etc. Is there ...
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Do i need additional IOs for this interface board?

I am designing a UI PCB which has an MCU which will interface with a main system controller (MSC) on a separate PCB. The UI PCB provides an initial power up to the MSC which then boots up its onboard ...
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2 answers
226 views

CAN bus communication. Issue with two slaves having same CAN ID

Does anyone know if it is possible to have CAN offsetting in case two slaves in same circuit transmits different data in same ID?? I have two slaves with same CAN ID transmitting data and I cannot ...
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2 answers
108 views

Is it possible to map pre defined data sets in PDO Mapping of CANOpen protocol

I've been trying to learn about CANOpen protocol and create a slave device accordingly. I understand that PDO mapping can be either static, or fully dynamic (according to CIA-301). My coding skills ...
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How to find the right components for the CAN bus signals merging?

I have 2 CAN connectors from 2 different devices and I want to design something that takes in both the inputs and gives the output on a single connector. In other words, I want to combine 2 different ...
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353 views

STM32 CAN Interrupt causes program to jump in infinite loop

Struggling with this issue for days now and can't find a solution. Maybe someone saw something like this before and can give me a hint. I have FreeRTOS running on an STM32L4 with different tasks. One ...
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Removing STM32F4xxx based HMI from CANBUS puts the network in BUSHEAVY state

I have a CANBUS with 3 devices on it. A PLC (CAN IO 14+, HAWE), a HMI (Barth DMA-20) and a 6 button CAN enabled button panel (Greyhill). The issue is, when I remove the display from the network (...
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1 vote
3 answers
444 views

CAN Bus Dominant and Recessive?

Why does CAN Bus represents signals with an inverted logic, high voltage for a logic 0 and low voltage for a logic 1? Is there any advantage in doing so?
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1 vote
3 answers
412 views

CANbus to USB adapter, is optical isolation worthwhile?

I have a motor whose driver board communicates via the CAN protocol. I need to programmatically command the driver board from my laptop computer using CANopen. I ...
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1 answer
46 views

Access device commands on Lenze 9400 Highline driver via Twincat3

I want to access the device commands on a Lenze 9400 Highline driver via CANoverEthercat(Twincat3). Is that possible and how can I do it? Specifically, I want to access the Device command 51: Identify ...
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2 votes
1 answer
499 views

Canbus, Opencan and ISO BUS

Quick question, I know about CanBus protocol. I'm interesting about ISOBUS and CanOpen. I ...
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2 answers
476 views

Selection criteria for microcontroller to read data from a car's CAN bus (from OBD2 to microcontroller)

I want to read data from a car's CAN bus using a micro-controller. The micro-controller is used outside the car (via OBD to micro-controller). A few micro-controllers i found with CAN interfaces are ...
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1 vote
1 answer
292 views

How to determine the length of the last data field in a SDO block transfer?

I've got a problem with the implementation of the CANopen SDO Block Transfer. The transmission is ok except the last block: ...
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1 answer
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CANopen addressing scheme?

TL:DR Using CANopen, don't see CANopen IDs on the bus. I'm very confused. I have a semi-functional CANopen network set up between a PLC and a motor controller. Those two items are the only two nodes ...
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