Change address range Siemens S7-315

Jeroen Benoot · Nov 16, 2009

Hi all,

I currently have a project where several Siemens PLC's are connected to each other with Profibus.
One master S7-315-2DP and 3 slaves, each with a CP342-5 card.
I have configured the master HW config in such a way that the I/O from the slaves via the CP start from EB500 for slave 1, 600 for slave 2 and 700 for slave 3.
The problem is that the address range of the master PLC is only up to E127.7!
In the manual of the CPU is see that it can be expanded to E1027.7, but I do not know how.
Can anyone help my on this issue?

Best Regards,
Jeroen Benoot

JesperMP · Nov 16, 2009

Hi Jeroen.

There are two methods.

1. You can expand the proces image of the CPU if it has this functionality. If it has, you find the parameters Size of Process-image input area and Size of Process-image output area under the CPU Properties and the Cycle/Clock memory tab. Notice that a very big proces image with big "gaps" will degrade the performance of the CPU.

2. Use the SFC14 DPRD_DAT and SFC15 DPWR_DAT to exchange the data from the i/o outside the proces image and some DB adresses. You then use the the DB adresses elsewhere in your program. This is the normally used method.

Jeroen Benoot · Nov 16, 2009

Thank you for the feedback.
Unfortunately I can not use method 1 as the CPU does not have that function.
As a reply to your second method;
I use the function 'DP_RECV' and 'DP_SEND' to transmit data to/from the slaves. This works fine, but the data reveived from the slaves is written by the function to EB500, ...
The CPU can not directly read from that byte/word as it is not in the address area. Is there a way to read from that area?
I will try usinge the function 'L PEW500', but I am not sure this will work.

JesperMP · Nov 16, 2009

I misunderstood something.
I thought that by "One master S7-315-2DP and 3 slaves, each with a CP342-5 card" you meant that it is the slaves only have the CP342-5 cards.
Ignore what I wrote before. It only applies if you use the integral DP port !
Why dont you use the integral DP port ?
Anyway, if the master also uses a CP342-5, then read THIS GUIDE, and follow "case a".
L PEW500 or similar will not work. The i/o image of the CP342-5 is not the same as the i/o image of the CPU.

Jeroen Benoot · Nov 16, 2009

The master PLC does use the integral DP-port.
I have made a testproject with 3 offline PLC's, one master (Integral DP port) and two slaves (CP 342-5).
The only difference now is that the IO config of the CP cards is outside the PI/O Area.
In my test I had configured the IO of the cards inside PI/O area, eg. EB 100. I used 'DP_SEND', 'DP_RECV' and that worked fine.

JesperMP · Nov 16, 2009

What you wrote before about using DP_SEND and DP_RECV with the master cannot be true. DP_SEND and DP_RECV works with a CP343-5, not the integral DP port.

Jeroen Benoot · Nov 16, 2009

I can send you the program if you want.
The communication is like this:
Master uses integral DP port, slaves each CP342-5.
Data is transferred via 'DP_SEND' and 'DP_RECV'.

In that way it works fine, so in my opinion these functions can be used with the integral DP port.

JesperMP · Nov 16, 2009

That is definitely new to me.
In DP_SEND and DP_RECV there is a parameter called LADDR.
LADDR is obtained from the setup of the CP342-5 in the HW Config.
Since you dont have a CP342-5, what LADDR do you specify ?

Jeroen Benoot · Nov 16, 2009

I think you misunderstood me, or I explained it wrong.
The master PLC does not use DP_SEND, DP_RECV. It read's it's data, I/O directly from the CP342-5 (IO configured in HW config).
The slave PLC's use DP_SEND, DP_RECV to send data to the CP342-5, which the master then reads.
The only problem now is that the configured IO of the CP cards in the master PLC's HW config are not in the PI/O address range.

JesperMP · Nov 16, 2009

If this was all the time about the master and its onboard DP port, why did you talk about DP_SEND and DP_RECV that only applies to the CP342-5 of the slaves ?
Oh well, never mind.

Like I said before, use DPRD_DAT and DPWR_DAT.

Additionally, the i/o adressing of the masters and slaves do not have to match. I400.0 of the slave can be Q36.0 of the master for example.
That said, it adds extra confusion, so it makes sense to line up the i/o images so that they are similar.

Change address range Siemens S7-315

Jeroen Benoot

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JesperMP

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Jeroen Benoot

Member

JesperMP

Lifetime Supporting Member + Moderator

Jeroen Benoot

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JesperMP

Lifetime Supporting Member + Moderator

Jeroen Benoot

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JesperMP

Lifetime Supporting Member + Moderator

Jeroen Benoot

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JesperMP

Lifetime Supporting Member + Moderator

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