Danfoss FC control via Terminal DI and Profibus

Dear All,

it is my first project with Danfoss FC and unfortunately I do not have the opportunity to test the desired function before commissioning.

So I please someone with experience to confirm these my assumption that I have obtained by reading the manual.

My task is to control this FC via Profibus OR via Control Terminal (digital inputs) with preset reference.


Is this good way to do it:

Selection between these reference sources is made by electrically setting or resetting DI on control terminal with programmed function "Preset reference ON" when [1] External/preset
has been selected in 3-04 Reference Function.

On Local Control Panel (LCP) during this "Auto ON" should be active.

Thank you,
KS.

I'm not really sure what it is you want to do.

If you are using profibus, then there is no need for preset reference.

If you set up your system in the simplest manner using e.g. PPO type 3, you will have 2 input word and 2 output words at your disposal.

Output word 1 will be your Control Word (CTW)
Output word 2 will be your reference (REF)
Input word 1 will be your Status Word (STW)
Input word 2 will bee your Main Actual Value (MAV)

Sending a 047C (hexadecimal) to your CTW will start the FC
Sending a 043C will stop it
Reference is in percent but using the hexadecimal value 0-4000 for 0-100%

If you do not like to handle the CTW on a word basis you can set the following (will give the same result):
Bit 2 = 1
Bit 3 = 1
Bit 4 = 1
Bit 5 = 1
Bit 10 = 1

All unmentioned bits should be kept at 0

And then by setting or resetting Bit 6 the FC wil start or stop.

But you need those bit set in order for the FC to run.

AND remember that Siemens swapps the bytes in the words.

Best regards,

Michal_dk

The description that Michal has given, is if you are using a Siemens PLC to control the Danfoss drive.

If it is something different you need to let us know.

I have examples I can send you using a CompactLogix PLC.

Cheers

Mark

Thank you very much for your reply Michal_dk and Mark also.

I want to control motor via Danfoss FC both with Profibus and via DI terminals.

I use Siemens PLC.

I know how to make Profibus control, but I am not sure if procedure from my first post is right to have control via Profibus and control with wiring on picture below.



Contacts -K2_40 and -K3_40 are contacs from LCB for Auto and Hand control and -K5_40 is contact from speed switch.

My primary question is do I have to set any parameter in FC so I could have control with both Profibus and wiring?

If you use the LCP and switch from "Auto On" To "Hand On" the LCP will show you a reference bar and by using the arrow keys on the LCP you will be able to adjust the speed of the drive.

What I guess you want to do is run the drive in a manual way using some push buttons?
Setting DI19 to "Preset Ref. ON" will ensure that onse you have activated that input you will have the Preset references available to you. But since I see you have a constant 24V on your DI32 "Preset ref. bit 0" I guess you only want a single speed. If this is correct you do not need the use this connection.
In the FC series there os 8 preset reference values, but only 3 bits to control them. So they are controlled by the logical value of the 3 bits.

Preset 0 : bit 0 = 0, bit 1 = 0 bit 2 = 0
Preset 1 : bit 0 = 1, bit 1 = 0 bit 2 = 0
Preset 2 : bit 0 = 0, bit 1 = 1 bit 2 = 0
Preset 3 : bit 0 = 1, bit 1 = 1 bit 2 = 0
Preset 4 : bit 0 = 0, bit 1 = 0 bit 2 = 1

And so on.

So for just one speed you would program Par. 3-10.0 to e.g. 500 rpm
I would leave DI18 and 19 as they are (from factory they are start and reverse) and use DI32 to select "Preset Ref. ON"
So by activating DI32 the drive will have a ref. of 500 rpm.
By activating DI18 the drive will start and run at 500 rpm.

But remember that DI27 is coast inverse, if you do not have a high signal on this the drive will not start. You can set it to "No function " in Par. 5-12 if you do not need it.

Thank you very much for your reply and effort.

Some things are much clearer to me now.

Yes, you are right I want to run the drive in a manual way using some push buttons with single speed. AND also using Profibus.

Can you give me advice what to do to have such control?

My assumption is when Preset Ref ON is high, then control is via pushbuttons and when Preset Ref ON is low control is via Profibus?

Not quite!

I'm at home now, so I do not have access to the manuals or MCT10 (free software for commissioning Danfoss drives - must have!)

BUT!
In Par. 8-01 "Control Site" you can choose where the control of the drive is comming from, here I would choose "Digital and Control Word", it should be the default value.
Now this "Preset Ref. On" is new to me, but I would imaging that what it does is to switch between having the reference comming from the PLC or from the local reference (e.g. preset and analog). If you choose Par. 3-04 "Sum" it will add all references and that will be your final reference, so that is NOT the selection I would choose here - if I understand the way the "Preset ref. On" function correctly.

Anything coming from the Profibus will still impact on the drive.

You could choose to use an input to switch setup, e.g. DI33 "Setup Select. Bit 0". Now by activating DI33 the drive will change from Setup 1 to setup 2, if you configure Par. 8-01 to "Digital only" the drive will stop responding to commands from the bus until you set DI33 back to 0.

Another advice I'd like to offer is this:
When you get your hands on your drives and motors.
1. Start by typing in your motor data in Parameter group 1-1 (size of the motor in either kW or Hp, motor voltage, Nominal frequency, nominal current and nominal speed.
2. Set Par. 1-29 "Automatic Motor Adaptation" to "Enable complete AMA"
3. Give the drive a Start signal (Hand On) and let the drive meassure the motor parameters of the motor.
4. Put in the Node address of the Profibus card in Par. 9-18
5. Power of and on the drive (all changes to the profibus communication parameters needs a power off before the take effect.

Thank you very much for your advices.

Especially this with Setup Selection, it seems to me like a great idea.

Hopefully, tomorrow I will have the opportunity to try all of this then I'll write here how did it go.