Qualified Personnel Only qualified personnel should be allowed to install and work with this software. Note draws your attention to particularly important information on the product, handling the product, or to a particular part of the documentation. Attention indicates that unwanted events or status can occur if the relevant information is not observed. Caution used without safety alert symbol indicates a potentially hazardous situation which, if not avoided, may. Caution used with the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. Warning indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury. These notices are marked as follows according to the level of danger: Danger indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
So in this case you must use SFC15 to write the prepared data telegram to the drive at one moment in your program.1 SIMATIC HMI WinCC V6 Basic Documentation Manual Order number Foreword 0 SIMATIC WinCC 1 Working with Projects 2 Working with Tags 3 Creating Process Screens 4 Dynamizing Process Screens 5 VBS for Creating Procedures and Actions 6 ANSI-C for Creating Functions and Actions 7 Setting up an Alarm System 8 Message Archiving 9 Archiving Process Values 10 Working with Cross-Reference Lists 11 Documentation of Configuration and Runtime Data 12 Creating Page Layouts 13 Creating Line Layouts 14 Setting up Multilingual Projects 15 Setting up User Administration 16 VBA for Automated Configuration 17 Communication 18 Release 04/03 A5EĢ Safety Guidelines This manual contains notices which you should observe to ensure your own personal safety, as well as to protect the product and connected equipment. the classic example is parameter access to a Siemens (Micro/Master) drive, where 4 words of data must be written to the drive as one single element written one by one, the drive will not acknowledge the data. You will need SFC14 and SFC15 when you need to read/write more than 4 bytes at a time, as a single element (Consistency by "Total") over Profibus, and that does not happen very often. If you were to use SFC14/ with those inputs, since they are addresses as I40 and Q40, your LADDR parameter would be set to w#16#28 (dec 40). You can read/write over Profibus up to 4 bytes (DWORD or REAL value) directly without any SFC. In the screenshot you are showing earlier, you have configured slave modules of one byte input and one byte output, with Consistency by "UNIT".
Please note that SFC14 and SFC 15 can only be used to read/write on a slave module, not on the full slave exchanges. You must use the confighured address for the module you wish to read/write to.
You must not use the Profibus address of the slaves (which is what I believe you are doing with the entries w#16#2 and w#16#3 in your code above), or the diagnostics address of the slaves. This is an extract from the System and Standard function manual. Please take a few seconds to look at the following illustration:
I suggest you look at this FAQ with sample code: That said, I havent actually tried it myself (didnt know of this variant until yesterday). The I_PUT and I_GET SFCs seems to do the job. So for a normal ET200 slave on a 315-2DP master you dont need this.
Cases where it could be required could be a VFD on DP, or other intelligent slaves (i.e.
You wouldnt need to read or write data consistently with a DP slave in most normal cases. It wont solve the problem of transferring more data than what is defined in the HW Config. This is just one part of the formula to exchange data with an intelligent slave. So with L and T instructions you risk that data in the target changes before you can read or write everything. If you try to use L and T instructions the max you can address is a doubleword (4 bytes). DPWR_DAT and DPRD_DAT is used to read and write data in one complete block (consistent data).