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FC51 Danfoss VFD MODBUS
I need to control a FC51 Danfoss VFD with LS PLC. I need to start , stop & jog the drives.

I have set all the parameters as per manual for Modbus operation at 9600bps 8n1.

I am unable to start the drive I am sending the following frame to start the drive:

Address of Drive 2
Function 5
Coil 6
Data 1

Can someone help me, Danfoss service Engineer has refused to help since I have not purchased the drive from their Official System House...

Your poll should like like this:
02 05 00 06 FF 00 6C 08

Thank you I will try it & post the result

I recommend you write the entire 16 bit control word versus only the start bit. This would satisfy the requirement that other bits (or hard wired digital inputs) be high to start the drive. Here are two examples:

Start drive, Run 40%:
Byte 0: 02 Address
Byte 1: 0F Force multiple coils
Byte 2: 00 Coil address Hi
Byte 3: 00 Coil address Lo
Byte 4: 00 No. of coils Hi
Byte 5: 20 No. of coils Lo
Byte 6: 04 Byte count
Byte 7: 7C Force data Hi
Byte 8: 04 Force data Lo
(047C-hex (reversed) is the control word to start the drive)
Byte 9: 99 Force data Hi
Byte 10: 19 Force data Lo
(1999-hex (reversed) is 40% of full speed, 4000 hex)

Stop drive, ramp to a stop:
Byte 0: 02 Address
Byte 1: 0F Force multiple coils
Byte 2: 00 Coil address Hi
Byte 3: 00 Coil address Lo
Byte 4: 00 No. of coils Hi
Byte 5: 20 No. of coils Lo
Byte 6: 04 Byte count
Byte 7: 3C Force data Hi
Byte 8: 04 Force data Lo
(043C-hex (reversed) is the control word to stop the drive)
Byte 9: 99 Force data Hi
Byte 10: 19 Force data Lo
(1999-hex (reversed) is 40% of full speed, 4000 hex)

Danfoss service and applications departments support all individuals regardless of the sales channel - even used products sold via Ebay. :) Perhaps you contacted an independent distributor who was not interested in supporting a product he did not sell. Please contact Danfoss at 800-432-6367 (North America) or download the instruction manual #MG02A402 at their website.

Bruce Widell
Danfoss Drives
Application engineer

Dear Mr. Bruce,

Thank you very much. I will try these setting once I am back in office tomorrow & posts the results.

I am sure Danfoss does not intend to discourage customers, but the application engineer from Danfoss, India, Bombay seemed to be the only guy knowing modbus interface and was not ready to share the details even over the phone, just because I took it from a reseller friend of mine.

Thank you once again

I , an application engineer from LS Automation & Danfoss Engineer, tried to establish the communication , but could not. When I want to communicate to a LS drive, I need to do the following

MOV 1 D0001 ; Write Enable
MOV 5000 D0002 ;Frequency 50Hz
MOV 2 D0003 ; Move forward

So I basically have to tell in their communication software xg-pd
1) Device No
2) Number bites to send
3) Trigger on which the command is sent
4) Starting address of data in my case d001 for the LS/LG drive
5) Memory Area to store the data 0x4xxxx

So please guide me what do I have to input into such registers for FC51 Danfoss Drives

Urgent help is appreciated

The answer to your questions will take a bit more space than available on this forum. I recommend you visit:

http://www.danfoss.com/BusinessAreas/DrivesSolutions/Documentations/Technical+Documentation.htm

Download the drive's instruction manual #MG02A402. Section "5: Modbus RTU" pages 24 through 39 of the manual provides the information you need.

I have no knowledge of the LS Industrial System's XG-PD software product so I can not help there. If you need additional help consider contacting Danfoss at hotline_usdde @ danfoss.com

Bruce Widell
Application engineer
Danfoss Drives
USA

Dear Mr.Bruce

I have already gone through the manual & can't just get it right

Dear Mr.Bruce

Thank you for your help Finally we got it working

> I have already gone through the manual & can't just get it right

074C reverse hex 3671

Well I am trying to interface 2 Nos Danfoss Fc-302 Drives to an Hmi, using Modbus rtu protocol. Till the System is Powered up the Modbus RTU Works Fine... But as soon as i Start Running the Motors, the Communication starts failing...

Tried Earthing .. but no difference..

Can someone Help

See these discussions of noise related to VFD's.

EMI from a VFD
http://www.eng-tips.com/viewthread.cfm?qid=262350&page=2

4-20mA signal plus VFD motor cables in shared conduit
http://www.eng-tips.com/viewthread.cfm?qid=261624&page=2

The latter is about 4-20mA control, but 4-20 runs on a pair of wires like Modbus does, and is just as subject to noise, even if RS-485 is a differential technique.

Note the comments by Ozmosis about 1/3 way down this thread about Rs-485 around drives.
http://www.eng-tips.com/viewthread.cfm?qid=211851

I try to communicate with Fc-302 to, i can read some parameter but i can't write the control word.

Please, can you help my with some advices.

By Etienne F on 21 March, 2012 - 8:41 pm

I'm using XG-PG to control a danfoss drive and a Omron temp controller Send me an email (dag82@hotmail.com)

and I will send you a program that start and stop the drive

You have to use user fram definited in XG-PG and write the hole command line (head, body and segment CRC16 as tail

Technical engineer,

I have the same problem, I use LS XBM PLC and Danfoss VLT MicroDrive.
How can I help communicate Mod Bush kg / pd software. I need to start, stop & jog the drives.

By indrajeet tupe on 8 March, 2010 - 1:09 am

hello sir,

i tried the same format which you have mentioned but i'm unable to receive the response from the drive. Instead wen i try to write a single coil the drive responds me properly but the motor is not starting.. could you please help me out with your guidance. looking forward to your reply.

> i tried the same format which you have mentioned but i'm unable to receive the response from the drive.
---- snip ----

> could you please help me out with your guidance. looking forward to your reply.

Send me an email (dag82@hotmail.com) and I will send you the complete modbus command to send to the drive. The best way to make sure that you send the correct command is to use a program call multiway to be able to read the message you send to the drive.

For the start command and write a speed command, you have to send the command 02 (modbus address of the drive) 0F (write multiple coil)
so the complete command line is:

020F00000020047c041999 and CRC16 number (validation number)
With this command line, you send the start command and forward command and speed command (1999 in HEX)

The register i'm looking for is the reset command and the read alarm from the drive... anyone know those register?

Hi,
I have this problem too.

I have set all the parameters to control the drive as modbus. I send even hex code to drive but I don't receive any response at all.
I think I have timeout error but I don't know how to solve it.

Would you please guide me what to do?!?

Best regards

To start the drive, you have to send the following string:

Send start-stop command and speed command to the drive:
02 0F 00 06 00 01 00 E6 82
Here's the command you have to send to the drive:
Start Motor: 02 0F 00 06 00 01 00 E6 82
Modbus command line:
02 = drive address

0F = Write multiple register command
0060 = 6000 reversed.. you have to write 0060 to send the frequency command 6000 and 6000 means 60 Hz

0100= start command (the first 02 is the drive address), (0F = write multiple register), (00 60 = 60Hz, 6000 reversedů you have to write 00 60 to write 6000 and it means 60 Hz) (register 0100 is the start command)

Replace 0100 by 0101 = stop command

Replace E6 82 by 27 42 = CRC 16 for the stop command (tail of the Modbus command)

E6B2 = CRC16 frame termination (this value is different for every command you send and receive; you have to be able to adjust the 4 last digit on variable. Here's an example. I write the command line for almost every operation (read and write to the drive)

Send me an email if you need additional information or if you need the way I use to find the command line you have to send to any Modbus device

DAG82@hotmail.com

Hi,

I have a FC302 as spindle VFD on my mill. For control I used MODBUS RTU on serial line, but I decided to change to MODBUS TCP using the option MCA-122.

So far so good and I am able to use most address registers for readouts and I can control the VFD by registers 2810 and 2811.

But since I installed the MCA-122 I am unable to write to coil registers like '6' for start/stop.

Doesn't the MCA-122 support coil registers? Or do I find them on other addresses?

Thanks
Uli