1. To make ByteStream Data There is a plan that the High Level Trigger (HLT) software uses the offline framework (Athena). HLT group wants to read in ByteStream data, convert them into Athena Objects and run their algorithms. They want to measure the efficiency of the conversion from ByteStream to Athena objects. As a result, we need to produce a fraction of the Monte Carlo data in the ByteStream format. To do so, we need to know the exact mapping between ROD, ROB/ROC etc.

2. The scheme Transient Data Store ByteStream – Raw Data format HLT/Athena Algorithms header trailer ByteStreamCnv

3. In principle, perhaps, LArRawChannelCollection should correspond to ROB (?). At the moment, we have LArRawChannelCollection Feedthrough no. in LArHardwareID ROD and FEB Channel : 1  1   ROD Channel

4. Data format and the mapping In order to modify LArRawChannelContainer to what it really should be, we need to know the mappings between FEB channel (feedthrough no./FEB slot/channel no.) and ROD – ROB - ROC. We do this only because the HLT group and upper management “ask” us to produce the Monte Carlo in the RawData (ByteStream) format. If somebody wants to do this, he/she is more than welcome to take up this job. The ROD Demo Board has defined the data format which has been used. It is probably close to what we want but... Eg. The PU in the RODDemo only holds half a FEB and the final PU in the final ROD probably holds 2 PU’s. Apart from that, we still need to know how the exact mapping in ROD- ROB-ROC. It will be nice if somebody can give it to us.

5. ROD Demo Board has defined the data format … 32310 0Beginning of fragment (0x00000B0F) Header 1Start of header marker (0xEEEEEEEE) 1Header size (0x08) 1Format version number 1Source Identifier 1Level 1 ID 1Bunch crossing ID 1Level 1 Trigger Type 1Detector Event Type Detecto r Data Status word 1No of PUPU MaskDetector Format Version Number Processing Unit 1 1Fixed Block #0 1Fixed Block #1 1Fixed Block #2 1Variable Block #3 1Variable Block #4 1Variable Block #5 Processing Unit 2 1Fixed Block #0 1Fixed Block #1 1Fixed Block #2 1Variable Block #3