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KM4 Driver Suconet-K FAQ
Question
Please see if you can find if there are any Intellution Drivers for SUCONET-K that support the Klockner Moeller EPC335 PC interface card ?
Answer
As far as I am aware KM Germany is standardising on FIX & they are suposed to supply the FIX (OR OPC) driver for this card.
That said however, I personally believe that the Serial driver is the better option in typical installations for the following reasons.
- Suconet-K is a Single Master & Slave(s) network. All KM devices have serial & Suconet-K ports. In a typical installation you have a lot of PLC-PLC comms which may be quite mission critical, So it is normally better to make one of the PLC's the Suconet master. Since you are programming the PLC's to get some IO PLC-PLC it is simple to get larger chunks from each PLC into master. What Better way to read the data from master -> SCADA than the serial driver ?.
- The serial driver is a lot cheaper.
- Some KM installations use both Suconet-K AND Profibus, If you had to support both in the SCADA this will get quite costly.
- You must understand that the network requirements of PLC IO & SCADA are quite different
- IO requires fast , regular transactions of small size
- SCADA needs random & slowwer access to larger chunks for memmory. SCADA reads large chunks regularly but normally writes seldom & randomly.
Disadvantage of the serial driver
not a multi drop protocol, so you need 1 serial port per PLC.
Performance Example
While serial may not be fast, it is fast enough if you organise the data in the PLC properly.
In our example we have 1 master & 7 slaves = 8 PLC's (master may be one with a smaller less critical program, closer to the SCADA)
- We allocate arrays of MW memmory variables to each PLC in the Master as follows (even if all are not used)
- 1 block of 32 MW's for input data for each PLC->SCADA (roughly 20 analogs & 160 digitals)
- 1 block of 32 MW's for output data for each SCADA->PLC (roughly 20 analogs & 160 digitals - setpoints)
- We program the code into the Master to get this data from the PLC's & pack it into the input MW's AND write the output MW's to the PLC's. Master does this continuosly every 0.5 sec.
In the KM4 driver config we have
- 1 channel running @ 9600 kbd
- 8 pollrecords for each input block polltime = 1 sec.
- 8 pollrecords for each output block polltime = 30 sec. (they do not change in the PLC so no need to read fast).
- database with 160 analogs & 1280 digitals inputs all updating @ 1 sec.
- database with 160 analogs & 1280 digital setpoints / outputs NEVER USE AO&DO - USE AR & DR INSTEAD.!!!
And voila you have a 2000 IO system updating @ 1 sec.!!
Note that the key to speed is packing as much IO as possible into the minimum pollrecords
Also See Tips on Optimising Most Drivers
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