Welcome Guest ( Log In | Register )

MEX Observations Temporarily Suspended, Solid-state memory problems
post Nov 2 2011, 01:20 AM
Post #1

Senior Member

Group: Members
Posts: 1065
Joined: 26-July 08
Member No.: 4270

MEX Observations Temporarily Suspended

-- Hungry4info (Sirius_Alpha)
Go to the top of the page
+Quote Post
Start new topic
post Feb 15 2012, 09:39 AM
Post #2


Group: Members
Posts: 239
Joined: 17-February 07
From: ESAC, cerca Madrid, Spain.
Member No.: 1743

MEX back to full science operations now. After a lot of work.


Go to the top of the page
+Quote Post
post Feb 17 2012, 03:55 AM
Post #3

Senior Member

Group: Members
Posts: 1266
Joined: 14-October 05
From: Seattle
Member No.: 530

QUOTE (cndwrld @ Feb 15 2012, 05:39 AM) *

This is a great writeup, btw. Came here to link to it!

I'm still curious what causes the SSMM errors, though. A comment here:
... suggests that the memory system is having bit errors.

Though in the way ESA describes it-- "errors during the transfer of data from the MTL(in the SSMM) to the command cache"-- I wonder if the errors occur not in the memory, but somewhere in a bus between the SSMM and the command cache in the CPU. They also suggest the redundant memory controller didn't do any better.

Page 127 here has a memory system diagram for VEX, pretty much like MEX:

That doesn't really help show which bus could be the culprit, though, because they're basically all redundant. I suppose it could be multi-bit-errors in the flash percolating all the way through either memory controller. Except the system should catch those. So I can talk in circles and not know what's really going wrong here. And I'm curious. Anyone know of any other sources?
Go to the top of the page
+Quote Post

Posts in this topic

Reply to this topicStart new topic


RSS Lo-Fi Version Time is now: 25th November 2015 - 06:21 PM
Please read the Forum Rules and Guidelines before posting.

Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.