Problem:
KRC4 with EK1100(EtherCAT) and EL6731(ProfiBUS master) with BK3150.
But I can't attach in WorkVisual the modules for BK3150! I have some KL1408s and KL2408s, but WV 6.0 didn't know them...
Don't pay attention to cyrillic words. It's easy to understand the problem - there is no the KL(14/28)08 for choosing in right column 
That i must import to project, and there i can download it? 
did you import all those moudles into WorkVisual DTM catalog?
my mantra is that when working with computers, one need to look at each file...
many things may not be visible when file is open by some fancy applicaiton.
so need to have separate look using independed software.... always.
that is the only way to know what is really inside. content is always interesting if you know how to look (even if binary)
so... you got yourself device desecription file for BK3150...
did you look inside?
what is the file size?
what modules are contained?
standalone device description file is small (few kB)
device description file for group of moduels are large (can be Mb)
did you try searching for KLxxxx inside the BK3150?
if the KLxxxx is contained but does not show up in WoV, then your WoV is not compatible with this DTM file.
go to the beckhoff Website and Download the gsd file. Not sure if this works but in s7 we sometime just assign 1byte as input instead of the exacts card description since this is a 1 byte input. This shoul work as long you have more Input assigned to the BK3150 than you actual use. You should also be able to assign 2 Bytes and just use 1. The bk3150 should be smart enough to allocated the addresses. If you planing using analog they need to go in first.
So you mean more hardware@ way... looks logically But KLхххх are standard. Maybe they are very old now?
Not sure if it is cause they are old or why they are missing. I assigned the bks before like that just by the amount of bytes. In the siemens s5 world this saved a lot of time since you can assign more than you use and just add a i/o card if you need one without reconfiguring the entire hardware config. which was a pain in the ass in the s5 world since you would have to burn the hardware config on a flash card. Just try it and see if it works.
Usually you use an Interrupt based on $MEAS_PULSE[x].
