Profibus Communication

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Thread Starter

Anonymous

Does anyone here have a sample program regarding communication of Siemens S7 and Micromaster 420 through Profibus module?

Please include on how to access the control word from the S7 program.
 
D

Daniel Chartier

Hello;

Here are the 2 basic steps to control a Micrmaster through Profibus with an S7 master (once the drive has recieved minimal parameters):

1) in Step 7, open the hardware Config editor. In tjhe catalog, select the Profibus module for your Micromaster (CB15 probably), drag it to the Profibus network line; give it a valid profibus address (same as you set on the drive's control panel); you will be asked what type of Profibus Profile to install, for this test select PPO3 (drag it to module no. 1 on the CB15 configuration table): no PKW (parameter words), 2 PZD (process data words).
Save, compile and download.

Using PPO3 simplifies the next step, accessing the drive through the program. When you installed the PPO3, addresses were attributed to the module, say 512...515 (4 bytes). Here is how they are used in the program:
PQW512: control word
PQW514: speed setpoint word
PIW512: control status
PIW514: actual speed status

2)In your program, write the speed setpoint to PQW514: MOVE hex4000 to pQW514 for 100% of the maximum speed parametrized on the drive; MOVE hex2000 for 50%, hex 1000 for 25%...
Then start writing to the control word PQW512; to start the drive clockwise, MOVE first hex 047E tro PQW512, then hex 047F (there must be a rising edge to the LSB). For anti-clockwise operation, MOVE hex447F to PQW512; to stop, MOVE hex447E.
Use PIW512 and PIW514 to read the status of your drive (Move them to a MWlocation, for example, so you can use them in a VAT table or a HMI program).

a suggestion: for trial purposes, trigger each move with a Mx.x bit that you control through a VAT table; this way you can see the immediate effect of each MOVE operation on the drive.

For more specific information, go to the Siemens support webpage and download the Standard drives manual. It will explain the differences between the PPOx profiles, and the use of every bit in the control word.

Hope this helps,
Daniel Chartier
 
> Here are the 2 basic steps to control a Micrmaster through Profibus with an S7 master (once the drive has received minimal parameters):

> 1) in Step 7, open the hardware Config editor. In tjhe catalog, select the Profibus module for your Micromaster
> (CB15 probably), drag it to the Profibus network line; give it a valid profibus address (same as you set on the drive's
> control panel); you will be asked what type of Profibus Profile to install, for this test select PPO3 (drag it to module
> no. 1 on the CB15 configuration table): no PKW (parameter words), 2 PZD (process data words).

---- snip ---

> 2)In your program, write the speed setpoint to PQW514: MOVE hex4000 to pQW514 for 100% of the maximum speed
> parametrized on the drive; MOVE hex2000 for 50%, hex 1000 for 25%... Then start writing to the control word
> PQW512; to start the drive clockwise, MOVE first hex 047E tro PQW512, then hex 047F (there must be a rising edge to the
> LSB). For anti-clockwise operation, MOVE hex447F to PQW512; to stop, MOVE hex447E

---- snip ----

I am performing the same operation but with COdesys on an Eaton drive with the PROFIdrive profile as well. I have downloaded the GSD, chosen PPO3 and identified the inputs (SW, ACT) and outputs (CW,REF). My confusion is: Do i need to write a program afterwards or does the application automatically identify the parameters according to the PROFIdrive? In other words when I simulate (write hex047f to the CW and hex1388 to REF) shouldn’t I expect a reading in the SW and ACT inputs? REALLY CONFUSED. any help would be great. Thanks
 
N
hi

I did CW-->Word0--> %QW1.4 and SW-->Word--> %IW1.4 in DP-module I/O Mapping but don't know how can AC500 recognize %QW1.4 is control word and %IW1.4 is status word .I couldn't find it.
 
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