S7-414F-3PN/DP Profibus Node Limit

Hi All,

It's been a long time since I visited this site, let alone posted anything. I hope the same excellent service still exists.

I need some help with the configuration of a Profibus network from the MPI/DP port on a S7414F-3PN/DP CPU. Part number: 6ES7 414-3FM06-0AB0. I've never had a problem with other CPU in the past but on this one I cant seem to configure more than 32 nodes. I keep getting the error message in the attached image. I have tried changing the configuration parameters to account for 2 repeaters. I have added the 2 diagnostic repeaters that will be on the network but it still wont allow greater than 32 nodes.

I checked the documentation and I'm pretty sure it can manage up to 125 nodes on this port.

Any help would be much appreciated.

Cheers

In the technical specification sheet it says for the DP port:
"Number of DP slaves, max = 32"

For the Profinet port it says:
"Number of connectable IO devices, max. = 256 "

You can add a Profibus CP card to increase the number of DP slaves, or change to Profinet.

I can see why you may be surprised.
S7-300 CPU´s with integrated DP ports can have max 124 DP slaves.
That the top-of-the-line S7-400 CPU (which arguably is intended for bigger plants with lots of DP slaves) only can do 32 DP slaves is not exactly logical.

Interface 3 is supposed to do 96 slaves
You have 3 interfaces

Ah !
That makes more sense.