About the usage of the SceneDMXcas.
Am I right in the following:
The start address is 301
The scene which will be selected with the value sent to 301, i.e. 8
The dimming level of scene 8 will be controlled by sending values to address 302
Is there a need to send the values to 301 and 302 in the same packet?
This is correct, as long as the DMX Start Address is set to 301, and the controller is sending 301 and 302 as described.
99.9% of DMX issues are wiring. You need to validate that both the master is using slot 301-302 and that the SceneDMXcas is set to 301 as well as a start address.