Extraction of all transponders SI data (NIT, MDT, SDT, EIT, TDT).
MDTs can be generated at any point in the transmission chain to signal missing streams (e.g. video, audio, subtitle or accompanied data) or Service Information components (e.g. NIT, SDT, EIT or TDT) within a multiplex.
The IRDs furthermore monitor the availability of the NIT, SDT, EIT and TDT (Time and Date Table) in each Transport Stream and shall generate a Multiplex Diagnostic Table and transmit it to the ASIUS processor, if a failure is detected.
These are the Network Information Table, the Service Description Table, the Event Information Table (EIT), and the Time and Date Table (TDT).
The local uplinks should generate such MDT in the case a service failure occurs for longer than 10 seconds, i.e. if a service component (video, audio, subtitle or accompanied data) or a Service Information component (NIT, SDT, EIT or TDT) is missing.