Problem: cannot write control word to VLT5000(danfoss), using S7400/IM467

Hello guys, I have a big problem with communicating with my drives.

I cannot send a Control word and Main Reference Value to my drive.
I'm able to monitor the inputs/outputs and the strange thing is that I can see my Status word and Main Actual Value (0607 = drive in stopped). If I operate the drive manually, I can see the STW and MAV changing... When I monitor the input/output modules in the drive, I can change the CTW (047F = to start drive) but nothing happens!


Setup:

S7400 CPU (6ES7416-3XR05)
IM467 (6ES7467-5GJ00)
Danfoss VLT500 drives
PCS7 7.1 control system

I have connected my drives to the IM467 module.
The IM467 module is operative without errors, the same goes for the drives. The CPU gives a message:

"more than one write data record (0 data records) has accumulated on the DP master. i.e. the DP master is temporarily working more slowly on the P bus than the CPU."

It has to do with the IM467 module.

The steps I have taken are as follows:

1. Installed GSD file from danfoss (DP0) (da030402.gsd)
2. Added drives to the hardware configuration and added PPO Type 5 Module consistent (also tried Type 5 Word consistent and Type 3 Module consistent)
3. Assigned the inputs to process image PIP1 and outputs to PIP2.
4. PIP are assigned to OB35/34 and called in CFC editor (PCS7 7.1 environment)
5. Bus address is configured
6. I set the following parameters:

Protocol = DP
Baud rate = 1.5 = same as master
Bus address = same as configured in hardware configuration
PPO Type 5 is selected
Function of control word bit 10 = Bit 10 = 1-> CTW active
Drivemode = Remote

Can anybody assist me on this? I've been busy with it for over a week now still no improvements...

Thank you,

Best regards,

I also tried on integrated DP master, but only see the statusword and drive won't react on my control word...

Same problem

Hi,

have you according to this manual? I mean are you using FC14 and FC15 => periferia outside process image area? Or do you use PQW address?

http://www.plcs.net/downloads/index...Profibus_communication.pdf&directory=Siemens&

I have only done this with PPO Type 3 Module consistent and CPU315-2DP.

Hi again,

manual seems a bit old for your pourpose. Anyway, can you see the control word changing from drive parameters? Parameter 967?

Edit: sorry, might not be accessible from control panel

Hi there,

I'm using the process image of the cpu.
I configured the inputs as PIP1 and outputs as PIP2 and assigned to OBxx.

So i'm writing into QWxx
I cannot access the CTW from the drive. It says its internal but I havent figure out how to access it.
Also, the LED on the Profibus option card is not flickering, so it means it doesn't communicate on profibus...

We found out (the hard way) when trying to get a VLT5000 to work from a S7-4xx via Profibus is that when the drives ACCEL time was set at one second it communicated but the motor didn't run.

So check some non-obvious parameters.

Hi,

so in your first message you mean that PIP1 is assigned to OB35 -> updated every 100ms(default). PIP2 is assigned to OB34 -> updated every 200ms(default).

Have you tried without PIPs and let the OB1 cycle update the IO? You could also try writing to PQW in OB1.

Hello guys,

thedave2: I try to change a few parameters, what you mean with ACCEL time, you mean Ramp up time? I have changed a couple of parameters, but there are more hehe. Maybe that helps...

Its so strange that I only can see my statusword changing
The drives were already configured 10 years ago, I'm now restarting a factory with a new plc, but they also uses DP protocol and the parameters seem right...

Anyway, I also tried OB1 and also access directly the PQW but no luck...

Well,
I give up... tried a lot of parameters.

Could you remember which one(s) it actually were/

I also checked the Bus configuration (starting at 500)
Inputs can be controlled in Logic OR or only Digital.
Also seems OK...

Hello guys,

|I found the problem and wanted to share it.

So i'm recovering an old plant which have VLT5000 drives.
All drives where connected with three wires on the serial inputs at the front of the drive.

+ voltage on pin 13
- voltage on pin 27 AND 29

The problem lied at pin 29--> This is a jog command and apparently when the drive recieves this signal, it will discard all other signals... So my CTW was written to the drive, but nothing was done with it because the jog command was active.
In the current situation, all drives were only able to jog at 10Hz... so a strange situation because a lot of drives are controlled by pressure transmitters etc..

But i'm happy now!!
Thank you for all the efford
Best regards...