From dennisb@cea.Berkeley.EDU Tue Aug 22 16:47:44 1995 To: darnell.r.tabb.1@gsfc.nasa.gov Subject: Post Pass real Time Data Cc: hun_tann@ccmail.gsfc.nasa.gov, kevin.hartnett@ccmail.gsfc.nasa.gov, bretts@cea.Berkeley.EDU, patr@cea.Berkeley.EDU, losik@cea.Berkeley.EDU, dennisb@cea.Berkeley.EDU Content-Length: 4712 X-Lines: 116 To: Darnell Tabb PACOR Systems Administrator From: Dennis Biroscak Re: Post-Pass Real Time Data (DB/EUVE/0072/95) CC: Kevin hartnett, Hun Tann, Brett Stroozas, Pat Ringrose, Len Losik This memo is in response to recent upgrades in PACOR & UCB capabilities to send and receive real time EUVE telemetry data in a post pass production format. This memorandum enumerates the current list of PACOR products that may be received by UCB and briefly describes the current operational understandings between UCB and Pacor. General: Telemetry and communications messages are formatted according to the Interface Control Document between the University of California at Berkeley and the Goddard Space Flight Center Mission Operations and Data Systems Directorate. The telemetry is transmitted to UCB via Data Distribution and Command System (DDCS) using TCP/IP X.25 protocols. The following types of telemetry data are sent from Pacor to UCB: 1. Realtime Data Real time telemetry data (32kbps) is sent to UCB from PACOR for every EUVE real time pass. Night and day telemetry is sent to UCB in separate transmission messages. There is no data accounting (data quality accounting) performed by PACOR on realtime data. Since simultaneous transmission of both realtime and production data can cause dropouts in realtime data, PACOR will not send any other data format while realtime telemetry is being sent. 2. Science Playback Data Each 512 or 1024 kbps tape recorder dump is forwarded to UCB within 2 hours of receipt at PACOR. The playback telemetry is forwarded using quicklook production mode to UCB via the DDCS link. Playback data is not merged with realtime data. Pacor does create separate night and day data sets and transmits the night data first. Occasionally, UCB may request a delay in the transmission or retransmission of science playback data. 3. Postpass Realtime After each 32kbps realtime pass, Pacor sends the realtime telemetry formatted as quicklook production telemetry with a data type of realtime. Pacor separates night from day telemetry in separate transmission messages, as is done for realtime messages. For passes where science playback data is also available, postpass realtime messages will be sent to UCB before science playback data. 4. Retransmission Requests UCB may request a retransmission of science playback data or postpass realtime telemetry. Requests for data less than 8 hours old are retransmitted within one hour of the request. Requests for data more than 8 hours, but less than 30 days old will be retransmitted within 8 hours. Requests for data over 30 days old will be retransmitted within 3 business days. 5. Science Playback Backlogs If, due to line or facility problems, a backlog of transmissions to UCB occurs, Pacor will give priority to original transmissions over retransmissions, night data over day data, and send the most recent data first unless otherwise requested. 6. Testing and Troubleshooting Occasionally, UCB or PACOR may need to troubleshoot line/system problems or test new capabilities and system releases by transmitting telemetry messages from Pacor to UCB. These telemetry messages will be clearly labeled as test messages (unless otherwise agreed by both UCB and Pacor), since receipt of test telemetry marked as normal telemetry will interfere with automated telemetry processing systems at UCB. UCB and Pacor will notify each other of any problems associated with the transmission of data as soon as practical after the problem is noticed. The ESOC is currently staffed 7 days per week from 8 am to 5 pm Pacific Time. ESOC personnel may be paged during off hours by calling the normal ESOC number 510-643-7087. Pacor is currently staffed 24 hours per day, seven days per week. All communication problems are worked during normal operating hours at each facility. However, exceptions are made for special circumstances on a case by case basis by operations personnel. Operational difficulties are resolved on a day-to-day basis via telephone or SCAMA (Switching, Conferencing and Monitoring Arrangement) line. Points of Contact for Pacor and UCB are: Pacor Operations: ---------------- Telephone: 301-286-7546, 7547 Fax: 301-286-2380 Darnell Tabb, NASA DPM Telephone: 301-286-3679 Fax: 301-286-1764 E-mail: Darnell.R.Tabb.1@gsfc.nasa.gov ESOC Operations: --------------- Telephone: 510-643-7087 Fax: 510-643-7362 Pat Ringrose Telephone: 510-643-7086 Fax: 510-643-7362 E-mail: patr.cea.berkeley.edu