Date: Mon, 09 Jun 2003 14:20:35 -0600 From: Henry Bland <henry@...............> Subject: Re: System Configuration
Karl Cunningham wrote:
>This is probably a question for Larry, but thought it might have interest
>
>1. Computer A is located near the seismometer, running the A/D card and
>SDR Server, powered from an UPS.
>2. Computer B, sitting next to Computer A running WinSDR, powered from the
>same UPS as Computer A. A short serial cable connects the two. WinSDR is
>set to act as a server over TCP/IP. This comptuer has a moderate-size hard
>disk and only keeps a few days of record files.
>3. Computer C, sitting in the house is running WinSDR, which is configured
>as a client to receive data from Computer B. This comptuer has a big hard
>disk for a month or two of record files and serves as my main WinSDR
>display. It also serves replay requests to WinQuake.
>4. Router/Firewall forwards TCP/IP request from WinSDR clients to comptuer
>B.
>
At the University of Calgary we've developed our own datalogger hardware
which works with the same microcontroller (a Rabbit) as Larry Cochrane's
datalogger. Our version uses a simple internet protocol for
communication rather than serial lines. Specifically, we transmit data
in short UDP packets. Our 4-channel datalogger is run-time configurable
using SNMP. Initial network addresses are obtained using DHCP so all
configuration can be done over the network. We currently can handle 4
channels of 24-bit samples at a rate of 2000 per second (we hope to
push this to 4000 SPS). Our logger works well, particularly with
off-the-shelf wireless access points. This configuration avoids the need
for a serial-network computer (and associated fan noise). The additional
hardware cost is negligible (see the ethernet-enabled core modules at
www.rabbitsemiconductor.com). So yes, it can be done. I am definately
interested in a low-cost commercial equivalent.
Are there any existing, open standards for *simple* continuous seismic
data communication over the internet? It would be great if dataloggers
such as Seismowin, WinSDR and Seislog could support an open standard for
simplistic network dataloggers. I know that Mauro Mariotti has shown
interest in adding streaming network support to Seismowin. I've written
a driver for Seislog to handle our network dataloggers. Is this a well
trodden path?
Cheers,
-Henry Bland
University of Calgary
.