Hi pylon,
you are right, was my mistake to write master and slave, so client and server is the right one.
I choose Modbus because i already use it for integers and it works good, and i was trying to use it again for strings... now you are make me change the plans... 
Is clear that is not my goal to to send the alphabet to the kepware, but it's just one example...
In fact i need to send two integers (part counter) and two strings with the part number with 10 char. The data will be shared with SAP and managed by SAP.
But my doubts is to choose the best driver for the Kepware that could be compatible with arduino. And Modbus tcp i already know something and with integers is working good.... I just need to put this information on the Kepware, after is other person that will manage this information in SAP.
As i'm not very expert on Kepware, i fond this way to work with integers, but now i need something more (strings) and i y can do it without change the driver on the Kepware will be perfect, but if with your recommendations i fond something different but if work, i'm open to test and investigate more about it.
Do you think that it can be more easy using MQTT and SNMP i will go investigate. To be honest i don't know what is it, but i will investigate.
If you have other idea, please share in the topic, i will appreciate.
Let me thank you for you support.
LC