Maximum Number of stations (wincc,op panel ,..) that can connect to a plc s400

Hi
I need your help
I want know that how many stations(wincc,op panel ,..) can connect to a plc S7-400 cpu417. According Technical Specifications of cpu417-4dp, maximum number of stations that can log on for message functions (e.g. WIN CC or SIMATIC OP) is 16 , communication functions for plc 417-4 Number of connectable OPs are 63 without message processing,16 with message processing.
Can you give me more information about this matter.
What is difference between stations with message processing and stations without message processing?
How many station(wincc,op panel ,..) can connect to a plc 417 and work without problem?

best regard

The message processing is for example ALARM-S.
If you do not use ALARM-S, then you can ignore this limitation.
In addition to the max no of connectable OPs, you also have to check the no of connections with a particular protocol.
Apart from that, do you really need that many OPs ?

Dear JesperMP
Thank you for reply

I don't get The message processing yet, Is ALARM-S something like alarm logging in wincc or not?Could you give me more examples?
I use Tcp/Ip protocol for connect 11 wincc station (HMI) to a plc s400 cpu 417 ,4 OPs (wincc flaxible) connected using Profibus to that plc also some time one or two persons connect to plc using step7 by Tcp/ip protocol.
Can I Increase wincc station to 13 Safely?

best regards

You should consider using server/client setup for the WinCC. In stead of 11 stand alone stations.
1 server, 11 clients, only needs 1 connection.
If you want to increase the amount of clients to 13, it shouldn't matter, because you'll still be just using 1 connection to the PLC.