DP_SEND and DP_RECV

HansAndersen

Member
Join Date
Sep 2006
Location
Hamburg
Posts
132
Hi everybody,

I could not find any useful information about this blocks for siemens s7-300.I would like to find out how can we use those blocks.When do we need to call the blocks in the project.There is a project in my hand that have these blocks.But I could not understand what the blocks say.I have attached a screenshot so that you can imagine what I say.

DP_SEND.JPG
 
Hans,
Just a few comments:
Normally FC1 is DP_SEND. Did you renumber it?

You normally send/receive from memory area (DB). Unless you have stretched your image are you sure you have that much addressable outputs (PQW Area)?

Nick
 
:/


Is there any way to communicate directly between two 315-2 DP (one master one slave) not using the configuration from HWConfig?

To send more then 4 bytes? To send whole DB perhaps?

I also wrote a post to this topic.
 
It's always a problem with two S7-300 as Masters. I would setup Master-Slave area to the max and write a block to transmit 200bytes at a time (a segment) and them block move from segment to holding block...them block move completed holding block out.

You'd be surprised how much data you can move on a quick network like Profibus.

Nick
 
L D[AR2 said:
Which CPU do you have in this system ?
S7-319 PN-DP

Nick B said:
Hans,
Just a few comments:
Normally FC1 is DP_SEND. Did you renumber it?

You normally send/receive from memory area (DB). Unless you have stretched your image are you sure you have that much addressable outputs (PQW Area)?

Nick
Yes.I know.I renamed it.The blocks are running properly.But I am confused on addressing.DP_RECV is using DB areas, though DB_SEND uses Q area.CP 342.5 acts as DP master in the system.
 
Last edited:
If you have two 319 pn/dp's then use Profinet and iMAP - you really can't go wrong . Before doing that I think you should decide what you are actually trying to achieve .

I would be very surprised if you were sending status of 2048 (Q) bytes in this manner , and I for one would always map this data to a DB first before making the transfer .

One last thing - switch the thing into ladder - I have just watched a guy sit for weeks trying to faultfind online with all STL code and interlinked sequences - he finally switched to ladder and realised he could see what was going on - with a very few exception ladder is so much easier to look at - I confine STL to those functions (indirect addressing /pointers / bit and byte manipulations) where it is really suited .
 
10BaseT. said:
If you have two 319 pn/dp's then use Profinet and iMAP - you really can't go wrong . Before doing that I think you should decide what you are actually trying to achieve .

I would be very surprised if you were sending status of 2048 (Q) bytes in this manner , and I for one would always map this data to a DB first before making the transfer .
.

I am using just one 319pn-dp.And two CP342.5 that use the DP_SEND and DP_RECV.
 
Hello Hans;

I have a funny feeling that there is some misunderstanding as to use functionnality of FC1/FC2. They are used to read/write to the DP slaves configured on the DP network on which a CP342-5 is master.

Just to clear things up, could you post a screenshot of the Hardware configuration in your program, showing the CP342-5 networks, configured slaves and input/output addressing? I think we could then make a link to the programmed blocks.

Hope this helps,
Daniel Chartier
 
dchartier said:
Hello Hans;

I have a funny feeling that there is some misunderstanding as to use functionnality of FC1/FC2. They are used to read/write to the DP slaves configured on the DP network on which a CP342-5 is master.

Just to clear things up, could you post a screenshot of the Hardware configuration in your program, showing the CP342-5 networks, configured slaves and input/output addressing? I think we could then make a link to the programmed blocks.

Hope this helps,
Daniel Chartier

Ideally need the config from netpro too - can't see the connections otherwise
 

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