About serial communication between Kawasaki Robot and Mitsubishi D-700 series

Quote from ksj

Question 1

Kawasaki Robot RS232C <-> RS232C to RS485 converter <-> Is serial communication possible between Mitsubishi D-700?

Kawasaki Serial Specification = RS232C

Mitsubishi D-700 = RS485

If your converter will convert RS232 to RS485, then the answer is yes.

However, you will need to construct your RS232 message in line with Mitsubishi requirements, which may require null terminations, line feeds, carriage returns in the RS232 coding.

Quote from ksj

Question-2

Have you ever tried question 1 if possible?

Or, if you have experience in serial communication with inverters from other manufacturers, please tell us.

Never tried anything like this before as from a VFD perspective, you are:

- Turning it on.

- Turning if off.

- Maybe reversing.

- Maybe controlling speed.

So for this, I would just use the Digital IO route that most VFD's come with.

Especially for speed control, most VFD's should have multi speed settings by way of a bit pattern (multi input) selection and programmable ranges.

What is it that you are intending the VFD application to be used on?

Ah right, so you are intending using digital IO to control the VFD from the Kawasaki.

Your original post suggested you wanted to use RS protocols to communicate between Kawasaki and VFD instead, no mention of a HMI.

So initially, you could easily setup the KLogic exchange between Kawasaki and VFD.

Create a small background task in the Kawasaki and use the teach pendants built in HMI (interface panel) to control the VFD.

This would be my first direction to take and prove the Kawasaki <> VFD control functionality.

I have done this before, except I used Profibus field bus between Kawasaki and a Siemens MM4 VFD.

With the HMI as being your user interface, then:

- If it has field bus available, I would use that and add the field bus to the Kawasaki, this would be simple.

- If the HMI only has RS232 comms or Ethernet (TCP/IP) available, then you would need to write programs to establish the communication path and will undoubtedly require more programming on both ends.

A member here claimed to have directly connect a HMI with a Kawasaki using modbus (ethernet ip option) which can directly access the modbus registers in the Kawasaki from HMI without having to write complex comms programs, but when asked to provide some sort of guide, or assistance they suddenly vanished and have never been seen, heard from since.

But if they were correct, then this is a direction to further explore, but this would require additional hardware in the Kawasaki - Modbus board (Ethernet IP).

In the interim, I would certainly look at setting up the KLogic, the robot teach pendant interface panel and connection to the VFD and at least get that part working first.

Would be very interested in hearing your progress on this?

You can tell me all you like about Mitsubishi inverters and post snippets of the manual here during the topic, but I have no intention of searching myself and doing any background reading other than what's presented on the forum, unless you want to pay me to research this on your behalf.

Sounds blunt I know, but you can appreciate, I am not that interested in learning about communicating with VFD's, unless I was creating the application myself but willing to assist in areas I can/experience in etc.

You need to decide on what you want to do, either using KLogic or RS232 then.

If it was me, KLogic all the way, simple digital IO exchange and an interface panel on the robot to start off with, this will ensure your walking before running.

What's your current Kawasaki experience?

VFD's are commonly used in automation, and are likely designed with control coming from a PLC.

A Mitsubishi PLC will already have the ability to communicate directly with a VFD (especially a Mitsubishi VFD), in which case the drivers and datagram (packets) will already be prepared by the PLC so the setup between PLC and VFD would be more like a plug and play scenario and selectable function block(s) within the PLC.

Most VFD's also include the proprietary serial interface which are more commonly designed to be controlled from a universal platform like a PC (windows, C# applications).

In order to make the VFD more universal to other PLC's or controlling devices, they may also offer fieldbus interfacing options for the VFD.

These interfaces may be via fieldbus (profibus/profinet/cc link etc) not usually by using the proprietary serial link.

Replacing the PLC with a robot and not using any common industry interfaces (fieldbus) will require the communication driver and datagram (packets) to be written from scratch using the robots programming language to deliver the correctly prepared datagram (packets) and will definitely require more work than you realise.

This means research into:

- VFD datagram format.

- Kawasaki AS Language commands to replicate the proprietary serial datagrams.

- AFAIK there will be no step by step guide provided by either supplier to simply copy from.

- Maybe examples of communications to a PC and application notes are available.

If you are set on RS232 route, attached is the HOST communication manual, which provides the AS Language commands available in order to establish communications and sending/receiving of data.

Note Section 3.0 Communication Protocol.

This is important to know in order to create a suitable driver to effectively communicate with the peripheral device.

Quote from ksj

Currently, VFD control through digital I/O has been successful.

The question starts out of curiosity.

I was curious about how to utilize K-Logic during the test demo cell configuration.

As mentioned, this would be my initial approach.

If you already have tested the digital IO control of the VFD, then as KLogic is Kawasaki software PLC option, this can be internally addressed so that it communicates with the digital IO board and therefore would be a more simplified interfacing option.

All that is required is to enable KLogic and then create a KLogic sequence in conjunction with the teach pendant interface panel (HMI) and your golden.

Attached is the KLogic Manual for your reference.

Note section 2.3.

This shows the internal software PLC (KLogic, KLadder) addressing to the digital IO board.

This would be very simple to integrate using this interfacing option.

Also attached is a video you may appreciate of a training suitcase I made back in the day containing:

- Siemens ET200 PLC.

- Siemens ET200 Profibus Master Module.

- Siemens MM4 VFD with Profibus adapter.

- 120 Watt induction motor.

- Weintek HMI.

Which I used to assist in training clients how to connect the Kawasaki Controller as a Profibus slave and control the VFD either by:

- HMI<>PLC<>VFD.

- Kawasaki<>PLC<>VFD.

I can also use a Profibus Master board to use and connect the Kawasaki as the Master and directly control the VFD without the requirement of a HMI or PLC.