Write Parameters to a VLT2800 on Profibus

I have an S7 project where I have a VLT2800 configured using PPO type 3 for basic stop/start control and speed reference. My client wants me to change this so we can use different acceleration times when they run a certain product type. I'm trawling through the Danfoss manuals trying to work out what PPO type I need and how to do it. I just wondered if anyone could save me a load of time by making available some sample code where they have done similar?

Any help would be greatly appreciated.

Barry

And for any purists out there, I'm not being lazy, they only dropped this on me today and I'm travelling up (a 6hr drive) on Sunday to do something else and they're hoping I can squeeze this in while I'm there.

Have a look at this manual http://www.danfos.info/content/files/PROFIBUS_DP_V1_Design_Guide_MG90E102.pdf

They are using the STD_FC from Siemens to telegram the drive

PPO type 3 is the simplest using only the Control word and Status word. If you then want to transfer data to and from the drive, you'll need PPO 4,5,6 or 8, depending on how much you want to transfer. Anyway, have a look at the example.

Here http://www.mchotline.com/Reference/MG90A502.pdf you'll find a nice description of the PPO types.

Thanks for the tips.

The first PDF is very helpful and seems to point to what needs to be done, I already have the other one. I suppose I was being a little optimistic that someone might have a few lines of code which I could copy & paste only having to change the node address to suit my drive. I guess that unless someone comes to my rescue I'll have to spend tomorrow reading the manual working out what needs to be done.

Thanks again,

Barry

Use PPO type 4 and set up subindex in parmeter 915 and 916 so you read / write parameter :
207 - Ramp-up time 1
208 - Ramp-down time 1

Now you can write the time and control that the drive have the correct time direct.

Look at page 34 in http://www.mchotline.com/Reference/MG90A502.pdf

When adding the drive for PPO type 4 this allocates 12 words of I-O memory area in the plc. I have the following in my predefined datablock from another project:

DB201
W0 - ctrl word
W2 - Speed reference
W4 - parameter 1 request
W6 - parameter 2 request
W8 - parameter 3 request
W10 - parameter 4 request
W12 - Spare wd12
W14 - Spare wd14
W16 - Spare wd16
W18 - Spare wd18
W20 - Drive status word
W22 - Drive speed actual
W24 - hs amps
W26 - hs torque
W28 - hs power
W30 - parameter 4 actual
W32 - spare word

I am sending the control word and speed reference using SFC15 (DPWR_DAT) writing 4 bytes to the drive starting at DB201.DBX0.0

I am reading the drive status using SFC14 (DPRD_DAT) reading 4 bytes starting at DB201.DBX20.0

The above is already in my code and is working but I need to understand how to do the following:

I want to set the acceleration value between 2 presets - 1)500ms and 2)3000ms. Acceleration value is parameter 207 and so where do I write the parameter number and value to be sent to the drive and does it have to be in a hexidecimal format or can I send integers?

I have to break into a working production line and implement this during a short break and so only really have one shot to get it right.

Any further help if possible would be much appreciated.

Regards,

Barry

Are the accel and decel reals or ints?
You will want another sfc for the 4 words of write

Apologies, I should add that the drive I-O is mapped from I/Q120 - I/Q131 hence my existing read and write addresses in the SFC's are set at W#16#78 (hex for 120 Dec).

I understand I will need another SFC. I only want to write the accel, not concerned with decel as it's set to coast to stop.

At the moment I have configured my code so the value is an Int which is set from a HMI screen in milliseconds. As I've never done this before and don't have a rig to test it I don't know what format the drive needs the value in. Was hoping someone could advise.

From reading the page of the manual that Jera advised I think I set the value of sub index 1 of parameter 915 in the drive to 207. What I need to know now is which address in the I-O memory do I write the value to and in what format?

My guess is that I use an SFC15 to write 2 bytes of data to W#16#7C (124 Dec).

Anyone?

This looks promising

http://www.nuovaelva.it/files/docs/Danfoss/Bus di campo/Profibus/Simatic S7/MN33A102 S7_FC300.pdf

Page 5 and 6

Thanks for that PLC,

I'm pretty sure I'm on the right track now. Only time will tell I suppose.

So! How are you comming along with this project?

Since you are using PPO type 4 you have 12 bytes or 6 words at your disposal.

By default PCD1 is the Control Word (CTW) and PCD 2 is the Reference Value (MRV) and Status Word (STW) and Actual Speed (MAV) for input. This is your first two output words (or Input for that matter). So QW120 is the CTW and QW122 would then be the MRV.

If you program 9-15.1 to 207 you will then have the the ramp up time as QW124.

All values to and from a VLT is 16 bit words, no Danfoss drives support real. By mapping two PCD channels you can get 32 bit words, but remember to map only 2 and 3, or 4 and 5 aso.

Michal_dk