4/11/2006 11:22 AM | |
Posts: 5822 Rating: (411)
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Hello rcivi, as said if you have a Byte, a Word or a DWord which is 1, 2 or 4 Bytes you can access the data directly over the process image. If you have 3 or more than 4 Bytes of consistent data you have to use the SFC’s. |
4/11/2006 12:07 PM | |
Joined: 1/3/2006 Last visit: 2/19/2024 Posts: 726 Rating: (71) |
HI there In my case I have used PPO type-4,PZD-6/6, to cmmuniate with 20 numbers of MM440 drives.It means lenght is 6 words. I have only used LOAD and TRANSFER (STL) function to send and receive data with drives. |
4/11/2006 2:01 PM | |
Joined: 4/10/2006 Last visit: 11/17/2023 Posts: 8 Rating: (1) |
OK, thanks both for your help. I will use the L and T instruction to access the data area of the MICROMASTER, because it seems to be the most secure method. Right now i´ll go for a commisioning and when i come back in a few days, i will tell you what happensn with this issue. Regards Ricardo |
4/15/2006 2:39 AM | |
Joined: 4/10/2006 Last visit: 11/17/2023 Posts: 8 Rating: (1) |
Hi Here i am, just coming back from the plant with the problem inverter. Well, first at all the PROFIBUS connection is working fine, i use the access via PIW and PQW to control the driver and everything goes smooth and easy. But, there is still a question that i want to share. The original problem was the access via SFC14/15, and i tried to make it work and i find that the problem is the firmware version of the CPU 414-3, because the SFC14/15 works well in 2 CPU´s with the firmware version 1.2, but in the firmware version 3.1 doesn´t work andi must use the direct access. |
4/15/2006 7:10 PM | |
Posts: 102 Rating: (3) |
HAi All There's one big difference in betweeen using Tehe Load Transfer statements and the use os SFC145 and SFC 15. For transferring the Acyclic data the SFC 14 and 15 are to be used but for the cyclic data only the use of Load and transfer data statements are preffered. Regards Shamsher |
4/16/2006 12:12 AM | |
Posts: 5822 Rating: (411)
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Hello, I will try to figure out if there is any new thing about the FW of the CPU V 3.1. Maybe I will get some information form some friends of mine. |
4/12/2010 2:45 PM | |
Joined: 2/17/2009 Last visit: 10/26/2010 Posts: 7 Rating: (0) |
Hi J_Bell, Did you receive in that time an answer about the problem with SFC14/SFC15 and data length of 4 bytes ? I too have the problem that the same S7-code using SFC14/SFC15 works well ina S7-300 but not in S7-400.Untill now, I have not found any explanation for this, and we had to change the program to 'regular' L PED and T PAD instructions. Has this something to do with firmware versions? Is there some more info to find since then? |
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