The BCS spectral data are stored in a queue memory prior to insertion in the telemetry frame. These data are therefore asynchronous to the data in the DP synchronous area of telemetry and occasionally the DP_SYNC data are not present at the same times as the spectral data. During these periods, deadtime correction to the spectral data are not possible. Key items relating to the mode being executed by the BCS are included in header information included in the queued data and it is always possible to know what mode the BCS is in.
At times a mode called ``Fast Queue'' is used. In this the data accumulators are sampled at intervals without clearing and then the data are stored in two different queue - normal and fast. The final integration before clearing of the accumulator is stored in the normal queue and all others are stored in the fast queue. In this mode, if the flare-flag is raised the fast queue is dumped to telemetry, but normally only data from the normal queue goes into telemetry. The mode is used at times when the spacecraft is in a mode whose bit-rate does not allow as short an accumulation time as is desired. The fast queue allows high cadence data to be stored and only output if a flare switches the spacecraft to a higher bit-rate.
Fast Queue data can be recognized by a sawtooth-type ramping in the light curve. These type of data are normalized by the IDL function BCS_NORM.