Which software do you need for the C7-621 module (with integrated AS interface master)?
The C7-621 device is an S7-300 with integrated AS interface master.
No additional software is required for normal operation.
You need a function block for extended operation. This function block is available together with manual for the AS Interface Master Module CP342-2 in Entry ID: 1123328 . Press the "Info" button to start downloading the function block.