Michael Wolf provided great phone support. When we reached a waypoint approximately midway between the two BMFC's, I was initally unable to get a response from either Node. Michael went through the acoustic modem setup, and he suggested setting S-Register S10 to 307. That enabled a long, 20 seconds or so, pulse train for the WakeUp command. An initial range of 1025 meters came back upon query from Node 3. We found 26,109 bytes stored in the data log. We were able to retrieve a 2-day report, but when we attempted an 8-day report, we repeatedly got CheckSum errors, and what little data did come back was mostly garbled. Next, on Node 4, it woke up and told us it was 985 meters away. 12,501 bytes were stored in the data log. We attempted 2-day and 3-day reports, which did send back some data, but again, what we received was mostly garbled. Due to the toroidal pattern of the transducer, Michael suggested moving the boat 500 meters at a right angle off the line connecting the two nodes, which initially appeared to provide a better signal-to-noise ratio, but we still were unable to retrieve long data logs. Next we tried moving off 1000 meters, with similar disappointing results. To avoid further depleting the Lithium batteries, we called it a day. All best ... Duane R. Thompson MBARI AUV Specialist drthom@mbari.org v: 831-775-2003 f: 831-775-1620 ----- Original Message ----- From: "Clare Reimers" To: "Duane Thompson" Cc: pgirguis@oeb.harvard.edu Sent: Thursday, March 22, 2012 10:25:01 AM Subject: RE: JHM cruise for Girguis Duane, Thanks for sending the data. What was recovered shows good performance from our microbial fuel cell systems. Can you explain the acomms issues? Could you just not maintain a link? Thanks too for going out for us. Clare -----Original Message----- From: Duane Thompson [mailto:drthom@mbari.org] Sent: Wednesday, March 21, 2012 3:08 PM To: Clare Reimers Subject: Re: JHM cruise for Girguis Hi Clare ... Acoustic comms were not good enough to permit us to retrieve long data files, but from what we did get, the BMFC systems have harvested energy since February. Michael Wolf provided phone support for quite a while. We tried repeatedly to capture an 8 day datafile, from both Nodes, but no joy. Usually nothing came back, and when something did return, it was mostly garbled.