FX3u communication with ABB drive via Canopen

[Clear.Mind 18]

Hello PLC guys. I need some advice for developing project. We have aim to rework mobile crushing complex. There are have 8 VFDs ABB acs 800 with CANopen Adapter Module
RCAN-01. We plan to use mitsubishi fx3u plc. I haven't work before with CanOpen protocol. Is it passable to programming communication between Fx3u-can and ABB drives or easier way to buy modbus or profibus communication options for inverters?

Before create topic, i have read RCAN-01 (3AFE64504231), fx3u-can (JY997D43301) manuals and sheet about canopen protocol.

I have also downloaded: 

1)Fx3u-can eds from mitsubishi.

2)RCAN eds from abb.

3)FX3CANopen_GW2_V120 libreary.

But i didn't understand how using eds files for configurating network. As i know mitsubishi haven't special software for it like profibus dp configurator for gsd. PDO it is like PPO for profibus?

I need just send to inverter CTW,Setpoint Ref and recieve from inverter STW,Feedback Ref, Current and alarm word. For modbus and profibus it is easy configurating via inverter's parameters. What types of PDO better use for this task and how it prepare?

Need i use NMT,SDO,Hearbeat?

Can someone give me example projects with canopen communication with any vfd in gid/gw2 or step by step explain what need to do?
 

[kaare_t 155]

Hi.

First of all I would recommend to use something you are familiar with since you're already rebuilding the entire machine/complex. There's always a learning curve with new things (and I would say that CANopen has a pretty "large" learning curve - at least when it comes to PLC's which are not "pre-defined" profiles). If you're familiar with Modbus or Profibus I would go with any of those if I were in your shoes.

However, if you still want to use CANopen I would recommend buying a software from a vendor that offers configuration tools for CANopen. One example I can recommend is from:
http://www.canopenmagic.com/. It is quite simple to use and you can import .eds files and configure your entire network from the tool. The settings you configure for the drive/PLC are stored in the flash memory of the respective units.

If you don't want to use a software (that you need to buy) to configure your network then you'll have to do it in the PLC program. This is the most "difficult" suggestion, and you'll have to gather a deeper knowledge of CANopen and the FX3U CANopen module. In essence you'll have to configure everything from the PLC program itself:

1. NMT: You need a network manager to control startup/shutdown/error handling of nodes etc.
2. SDO: You'll need to code sending SDO's to configure your nodes (including the FX3U CANopen module itself)
3. Heartbeat: Not critical, but highly recommended since you're running VFD's
4. PDO: You'll need to configure every PDO and their respective mappings according to the specifications of the ABB .eds file and the FX3U mapping of PDO's

Basically the FX3U CANopen module is a "barebone" module with very little (in my opinion nothing really useful) configuration preloaded. So what you need to do is setup sequences of code to configure the module when the PLC boots. This sequence must contain everything needed to run your specific network. This includes sending SDO messages to both other nodes, and to the FX3U CANopen module itself (pingback messages). Since you're in the programming software you can not visualize which settings you are modifying hence you must "know what you're doing". I would recommend digging into the CiA DS301 specification ("Communication Profile" specification). If you're still interested you can take a look at the following (not required but recommended for better undestanding): DS302 ("Framework for Programmable CANopen Devices"), DS405 ("IEC 61131-3 programmable device (PLC)"). In addition you have DSP402 ("Drives and motion control") but I think you have to pay for this specification. Check out: http://www.can-cia.org/

And as a small side note: If I for some reason need to develop PLC code, I always use the CANopen software tool in addition. This is because there are several hundred (sometimes thousands) of different parameters, which can be adjusted to combinations of almost endless possibilities. By using both PLC code and the software I can write code, send it to the PLC which sends out the commands on the bus and then see the  changes in the different units using the software. I would say that no matter what you do in CANopen, always use a software to verify the command output.

I can also say that the advantage of CANopen (since I've just listed a lot of complex and "negative" points about CANopen) is to have a more or less self-configured network of devices. Many devices (excluding PLCs) have a specific predefined set of variables (more predefined than gds files from Profibus) so you can often switch between different brands of equipment (e.g. an encoder) and the network still configures itself automatically and everything just works. This is of course not always the case, but can be done if the hardware is selected properly. CANopen can also be highly deterministic and you have very good control over errors and errorhandling, network management and failover situations, priority of messages and so on.

So to summarize: If you can (probably the cheapest option by the way), I would go with something you're already familiar with and buy the extra hardware - it will most likely be the cheapest option in the end. If you "must" use CANopen, I would buy a configuration tool so that you're able to visualize the settings you are modifying. If you don't want to purchase everything (but spend weeks of development and debugging) then you can read up on the links provided above. In any way, feel free to ask questions in the forum if you run into issues in the process.

EDIT: Added link to CAN in Automation site.

Edited 4 Nov 2016 by kaare_t