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Results 251–263 of 263

Transmit TEP Operations

Specification • Transmit TEP ACKs A transmit TEP shall not send an ACK packet. Transmit TEP Sequence Number Allocation Each DATA packet transmitted shall have a sequence number allocated from the TEP's transmit window range of available sequence numbers. CONTROL Packet Sequence Number All CONTROL packets shall be transmitted with a sequence...

Communication Specification > SpaceWire > Protocols > JAS Reliable Data Delivery Protocol > Channel Operations > Transmit TEP Operations

Urgent Messaging

Specification • Urgent messaging is a best-effort priority communications path that does NOT provide for reliable delivery, missing packet detection, or out-of-sequence packet reordering. It may optionally be implemented in this protocol to facilitate an out-of-band transport pathway that may be useful for such things as time broadcasts, exception/error control, meta messages,...

Communication Specification > SpaceWire > Protocols > JAS Reliable Data Delivery Protocol > Overall Functional Description > Urgent Messaging

Useful Metrics for Analyzing Topology Candidates

Other • Emerging high-bandwidth, low-latency network technology has made network-based architectures both feasible and potentially desirable for use in satellite payload architectures. Network architectures are capable of routing large amounts of traffic with reasonable latency, allowing considerable amounts of data between nodes to be shared. However, care must be exercised when developing...

Joint Architecture Standard Overview > Network Topologies > Useful Metrics for Analyzing Topology Candidates

Vacuum Impact

Specification • The JAS electronics shall consider testing in a thermal vacuum environment because inadequately heat-sunk parts will fail/burn-up. Overheating is the issue, exceeding maximum junction temperatures.

Mechanical Specification > Environmental Exposure > Vacuum Impact

Venting

Specification • The JAS mechanical structure shall have no confined or captured volumes. Venting ports shall be provided to prevent damage, or the release of gases, due to pressure changes during testing, transportation, and launch. Threads need not be vented.

Mechanical Specification > Environmental Exposure > Venting

Vibration (Random)

Specification • The JAS housing support shall meet all performance specifications after being subjected to the vibration level prescribed by figure 5.5.1. This spectrum shall be applied, to the mounting brackets.

Environmental Specification > Vibration (Random)

Volatile Memory Storage

Profile • The CH profile may also operate as a low- to medium-performance memory node, hosting volatile SDRAM memories that can store mission data for short periods of time. This application may be used to queue mission data, provide temporary storage of data for processing, and other similar functions. Volatile Memory Storage...

Command and Host Processor Profile > Applications > Volatile Memory Storage

Volatile Memory Storage

Profile • The RP profile may operate as a high-performance mass memory node, hosting volatile SDRAM memories that can store mission data for short periods of time. This application may be used, for example, to queue mission data or temporary data storage for processing. Volatile Memory Storage Instantiation In this application, the...

Reconfigurable Processing Profile > RP_Applications > Volatile Memory Storage

VPX

Specification • While no specific node-to-node interconnection method is specified in JAS it is highly recommended that the nodes make use of a standards-based chassis and backplane such as VPX defined by VITA. The VPX standard provides high-speed switched serial interconnects between plug-in modules or nodes while providing for parallel bus interconnects...

Electrical Specification > Electrical Interconnects > VPX

X,Y, and Z Axis Random Vibration

Specification • The JAS support shall meet all performance specifications after being subjected to the random vibration environment prescribed by the figure below. Note that these are acceptance levels. This input should be used along with the program Strength Qualification Plan. Random Vibration

Environmental Specification > X,Y, and Z Axis Random Vibration

Results 251–263 of 263