Dear Roalnd,
thanks for making a test scenario of DCD function, but let me explain my scenario on EC21-E TE-A connected to UMTS<E EVB Kit and using Telekom SIM card. after registering on the Network and activate the PPP connection then i get DCD on, after that i disconnected the Antenna and wait for 24 hours the DCD remain On.
Best Regards
Wessam