S7400 and S7300 Profibus Network

Hi all,



I am working on an existing Profibus network that has an S74142dp as the master and 7 X 3152dp as slaves. I am adding another 3152dp as a slave.

THe first issue I have is inside in the hardware config of the S7414 I notice an ‘X’ over the CP443-5 card (I have 2 separate Profibus networks) On investigation it informs me there is a mismatch between the configured and actual. On checking there is. The HW config has card number 6Es7 XXX-XXX01-XXXX (I don’t have the card number in front of me) where as the card is 6Es7 XXX-XXX03-XXXX. If I replace this card with the correct and download my HW config then I loose all connections to the 7 3152dp’s?? Re-loading the old code solves the issue??




In my new slave I have a bus fault. I’m certain my config is ok. The new slave is now the second last slave on the Profibus cable and if I switch on the resistor on the connector then my bus fault goes away. I am due to visit the site again to investigate further but I suspect that it’s a cabling issue?


Any thoughts on the two issues.

Thanks.

Hi ylade.

1st check the exact typenumbers of the CP443-5 cards, installed and in STEP7. If they are same type number "family" then you can exchange the module in STEP7 without losing the configuration.
Examples
6GK7443-5DX01-0XE0 and 6GK7443-5DX03-0XE0 is OK.
6GK7443-5XF01-0XE0 and 6GK7443-5DX03-0XE0 is not OK.

If that part is OK, then the important trick is to not delete the CP443-5, but in stead drag-and-drop the new CP443-5 from the HW catalog onto the existing CP443-5 in the rack. That will keep the configuration.

About the bus fault. As you describe it, something is wrong in the cables, or the connectors. That, or the last slave is switched off. If that can happen in normal operation then you need an active bus terminator at the end of the bus. Must be supplied with same 24V as supplies the master.

Hi JesperMP

6GK7443-5DX01-0XE0 and 6GK7443-5DX03-0XE0 THis is the exact part numbers I am dealing with. I use the function within the HW config 'Replace Object' Checking the configuration it is ok.



S7414------Other Slaves.....----------Problem node-------Last Node


The Last node has the connector set to 'On'. I have a 'Bus' fault on my problem node and the last node is working fine. If I change the Connector to 'On' my Bus fault disappears on my Problem node. Obviously the last node then has a bus fault as my new node is my Enf of Line.

Also, on seperate issue When I complete an upload of the S7400 my hardware config displays all the S7315 nodes without addresses? Just empty brackets?

Thanks

Very odd behaviour.
I take that you have configured both 315-2DPs in the project, and not downloaded the same project to both nodes ?
You can check the HW diagnostics on both cases to see what node address is missing.

One thing that can really confuse matters is if the cables enters and leaves the Profibus connector in the wrong order. The cable that comes from the master end should enter where the arrow points inward towards the CPU.

Edit: Also check that the terminator is ON at the last node.

Dont know about the other upload problem.
The few times I have done it the i/o addresses gets uploaded OK.