Something that I want to look at is the coherence between seismic motion and PRM motion. Since Den has been working on the fancy new seismometer installations, I got caught up for the day with getting the new corner seismometer station set up with a T240. Later, Rana pointed out that we already have a Guralp sitting underneath the POX table, and that will give us a good first look at the coherence. However, I'm still going to write down all the cable thoughts that I had today:
The cables that came with the electronics that we have (from Vladimir and tilt meter -land) are not long enough to go from the seismometer to 1X7, which is where I'd like to put the readout box (since the acquisition electronics are in that rack). I want to make a long cable that is 19pin MilSpec on one end, and 25pin Dsub on the other. This will eliminate the creative connector type changes that happen in the existing setup. However, before making the cable, I had to figure out what pins go to what. So.
25pin Dsub 19pin MilSpec
1 P
2 N
3 E
4 No conn
5 D
6 R and V
7 H
8 J
9 No connection
10 T
11 F
12 L
13 No conn
14 B
15 A
16 R and V
17 No conn
18 C
19 G
20 G
21 K
22 U
23 No conn
24 S
25 M
I am not sure why R and V are shorted to each other, but this connection is happening on the little PCB MilSpec->ribbon changer, right at the MilSpec side. I need to glance at the manual to see if these are both ground (or something similar), or if these pins should be separate. Also, I'm not sure why 19 and 20 are shorted together. I can't find (yet) where the short is happening. This is also something that I want to check before making the cable.
Den had one Female 19 pin MilSpec connector, meant for connecting to a T240, but the cable strain relief pieces of the connector have 'walked off'. I can't find them, and after a solid search of the control room, the electronics bench, and the place inside where all of Den's connectors were stored, I gave up and ordered 2 more. If we do find the missing bits for this connector, we can use it for the 2nd T240 setup, since we'll need 2 of these per seismometer. If anyone sees mysterious camo-green metal pieces that could go with a MilSpec connector, please let me know. |