TIA v19 - CB1241 communication stuck on BUSY

Hello,

I am currently running TIA v19 Professional. I am woriking on a project where I need to implement RS485 modbus communication with several serial devices on the chain.

I started of by creating a clean project (tought this was the issue) in TIA v19. I added my plc to the project, in this case a S7-1214C DC/DC/DC (6ES7 214-1AG40-0XB0) firmware version 4.5, as this it what it came with from the factory, and I succesfully connected to it, no issues.

In device configuration, I selected a CB1241 from the Communication Boards folder, and selected version 1.0 as it is the only one available, and the one I always used in the past. I then configured the CB as follows: speed(38400), parity 2(even parity), 1 stop bit.

After this hardware configurations, I selected the MB_COM_LOAD port that was allocated to the CB (269 in my case) to the port parameter of MB_MASTER and used the MB_LOAD and MB_MASTER (both version 2.1, and 2.0) blocks of the MODBUS library, with the proper input-output parameters connected. 

Unfortunatelly, after the first REQ is received in the MB_MASTER block, the BUSY output goes TRUE, and stays that way no matter if i turn the REQ param ON/OFF. In the past even if there was a timeout the BUSY bit would eventually go FALSE, but now it seems to get stuck in the true value, and no LED's are blinking on the CB.

Attached a few screenshots, to help understand my issue. Thank you all for your time reading this, and for any ideeas or help you might be able to provide.

Have a great one :)