[PLC4X-240] Protocol error in reading string

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0
• Component/s: Driver-S7
• Assignee: Christofer Dutz
• Reporter: Stefano Bossi
• Created: 20/Aug/20 07:49
• Updated: 20/Aug/20 14:49
• Resolved: 20/Aug/20 14:49

Description

Dear Christofer,

unfortunately I have found an another issue.
Via the HelloPlc app I am trying to read a string from my 1200 PLC; here attached you could find the screenshot of the DB as configured in the PLC.
The command line I am using is:

"--connection-string 's7:tcp://192.168.1.192?controller-type=S7_1200' --field-addresses '%DB1:6.0:STRING'"

With the library Version 0.8.0 after the patch Julian introduced here: Pull 175 which fix the reading of Array of numbers, the reading of Strings doesn't work any more.
The error I could read via wireshark is:

[Error code: S7 protocol error: Wrong frames (0x8500)]

With the library version 0.6.0 the string is correctly read.
To help you in your work I have attached a capture with both the library version.
Hope to be useful to fix the bug.

Regards,
Stefano Bossi

P.S. just to let you know, I am trying to read a complex DataBlock and this is the reason I am experimenting with a lot of different types of variables. In the near future I will try to read some many other and to write some too. Unfortunately your code is far too complex for my java knowledge and I am not able to fix the bug by myself but I could test the library and send detailed report if I found some trouble. Hope this could help anyway.