The Traffic Generator (TG) Add-On allows you to transmit messages (in parallel of your capturing process) – With this Add-On you can create, edit and transmit messages from a Perytons Format (.anl) file or, when combined with a Scripting Add-On module, transmit messages based on a message that has been received, etc.
Regarding the option to transmit messages with erroneous FCS on purpose, internal tests with several of the dongles supported by our TG Add-On (Telegesis, Dizic, DE) gave results that the FCS is always calculated and transmitted by the dongle itself and the TG can’t control its value (most probably this is done in the dongle HW and not even by its FW…).
This means that packets transmitted by analyzer TG Add-On will always have a valid FCS calculated value.