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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-NZ link=blue vlink=blue><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I’ve just been going through tidying up my Linux image and came across /etc/ethercat.conf.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The documentation refers to using the /etc/init.d/ethercat script and /etc/sysconfig/ethercat as its configuration file.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>However I also found /etc/ethercat.conf which is called from usr/sbin/ethercatctl. Are these ones obsolete?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Graeme.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> etherlab-users-bounces@etherlab.org [mailto:etherlab-users-bounces@etherlab.org] <b>On Behalf Of </b>Graeme Foot<br><b>Sent:</b> Thursday, 22 March 2012 12:44 p.m.<br><b>To:</b> etherlab-users@etherlab.org<br><b>Cc:</b> Ralf Rösch<br><b>Subject:</b> Re: [etherlab-users] Patch for Distributed Clock<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'>Hi,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'>I just noticed yesterday that I had forgotten to initialise the dc_ref_slave variable, so it would sometimes get an opps on startup. I have also added the extern "C" define to ec_rtdm.h (provided by Ralf Wiegand).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>Ralf Rösch (below) </span><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'>has also asked for a bit more detail as to how I'm using the reference slave as the dc clock master so I've also added another example (examples/rtai_rtdm_dc). Let me know if it fails or something is not clear enough (I've built it without errors but haven't had a chance to test it, fingers crossed).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'>I have attached the updated patch.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'>Graeme.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";color:navy'><o:p> </o:p></span></p><div><div class=MsoNormal align=center style='text-align:center'><span lang=EN-US style='color:windowtext'><hr size=2 width="100%" align=center></span></div><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> Ralf Rösch <a href="mailto:[mailto:ralf.roesch@rw-gmbh.de]">[mailto:ralf.roesch@rw-gmbh.de]</a> <br><b>Sent:</b> Thursday, 22 March 2012 09:30<br><b>To:</b> Graeme Foot<br><b>Subject:</b> Re: [etherlab-users] Patch for Distributed Clock</span><span lang=EN-US style='color:windowtext'><o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-GB>Hi Graeme,<br><br>thanks a lot for your great job.<br>I would like to implement your way of syncing DC under RT PREEMPT.<br>Do you have a more detailed example for using your method.<br>I do not understand completely your description below. <br>The best explanation would be piece of source code.<br>May be you can collect the relevant sections 1) .. 4) of your source?<br><br>Thanks a lot in advance<br>Ralf<o:p></o:p></span></p><pre><span lang=EN-GB>Roesch & Walter___________________________________________<o:p></o:p></span></pre><pre><span lang=EN-GB>Industrie-Elektronik GmbH * Tel.: +49-7824 / 6628-0<o:p></o:p></span></pre><pre><span lang=EN-GB>Wörtelweg 2b/c * Fax: +49-7824 / 6628-29<o:p></o:p></span></pre><pre><span lang=EN-GB>D-77963 Schwanau * <a href="mailto:ralf.roesch@rw-gmbh.de">mailto:ralf.roesch@rw-gmbh.de</a><o:p></o:p></span></pre><pre><span lang=EN-GB>Germany * WWW: <a href="http://www.rw-gmbh.de">http://www.rw-gmbh.de</a><o:p></o:p></span></pre><pre><span lang=EN-GB>Amtsgericht Freiburg i.Br. HRB 391345<o:p></o:p></span></pre><pre><span lang=EN-GB>Geschäftsführer: Dipl.Ing.(FH) Ralf Rösch, Dipl.Ing.(FH) Martin Walter<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>GnuPG key: 52ECD70F 2010-09-04 [expires: 2012-12-31]<o:p></o:p></span></pre><pre><span lang=EN-GB>Fingerprint: 8415 9113 5F05 D579 6685 D5AD 5CE7 5429 52EC D70F<o:p></o:p></span></pre><p class=MsoNormal><span lang=EN-GB>On Thu Mar 15 2012 02:09:49 GMT+0100, Graeme Foot <a href="mailto:GraemeF@touchcut.com"><GraemeF@touchcut.com></a> wrote: <o:p></o:p></span></p><pre><span lang=EN-GB>Hi,<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>As part of my dabbling into getting my distributed clock stable I have<o:p></o:p></span></pre><pre><span lang=EN-GB>made a couple of changes.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>I have attached two patches:<o:p></o:p></span></pre><pre><span lang=EN-GB>- etherlabmaster-1.5-2266-a_rtdm_dc.patch -> all my rtdm and dc changes<o:p></o:p></span></pre><pre><span lang=EN-GB>- etherlabmaster-1.5-2266-c_dc_clock_fix.patch -> just the dc clock<o:p></o:p></span></pre><pre><span lang=EN-GB>changes<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>My primary problem was an unstable master clock source. In tracking<o:p></o:p></span></pre><pre><span lang=EN-GB>down what the problem was I also checked out what TwinCat was doing.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>TwinCat has three distributed clock modes:<o:p></o:p></span></pre><pre><span lang=EN-GB>- (default) Master time/cycle updated to match ref slave time<o:p></o:p></span></pre><pre><span lang=EN-GB>- Ref slave time updated to match Master time<o:p></o:p></span></pre><pre><span lang=EN-GB>- Master time and Ref slave time updated to match an external clock<o:p></o:p></span></pre><pre><span lang=EN-GB>source<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>TwinCat also allows you to choose which slave to use as the ref slave.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>TwinCat uses datagrams:<o:p></o:p></span></pre><pre><span lang=EN-GB> ARMW 0x0 0x910 (sync slaves to ref)<o:p></o:p></span></pre><pre><span lang=EN-GB> APWR 0x0 0x910 (sync ref to master)<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>and replaces the second datagram with a NOP when its not required.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>The EtherLabs master uses datagrams:<o:p></o:p></span></pre><pre><span lang=EN-GB> APWR 0x0 0x910 (sync ref to master)<o:p></o:p></span></pre><pre><span lang=EN-GB> FRMW 0x1 0x910 (sync slaves to ref)<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>with no sync ref to master when its not required. (ARMW vs FRMW<o:p></o:p></span></pre><pre><span lang=EN-GB>shouldn't make any difference.)<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>In my system I have two issues:<o:p></o:p></span></pre><pre><span lang=EN-GB>- My master clock (although it is now stable) gets a jitter of +-5000ns<o:p></o:p></span></pre><pre><span lang=EN-GB>(though usually +-2000ns) between the call to get the system time and<o:p></o:p></span></pre><pre><span lang=EN-GB>when the frame is actually sent out to the slaves. This will be, I<o:p></o:p></span></pre><pre><span lang=EN-GB>assume, due to various code paths being called during the master_send.<o:p></o:p></span></pre><pre><span lang=EN-GB>- My Beckhoff CX1100-0004 coupler does not seem to be a stable ref<o:p></o:p></span></pre><pre><span lang=EN-GB>slave.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>So what I've done is decided to use the default TwinCat method where I<o:p></o:p></span></pre><pre><span lang=EN-GB>pick a ref slave and update my master time based on the ref slave time.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>What the patch includes:<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>1) ecrt_master_setup_distributed_clock()<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>Lets you set the masters application time and choose a ref slave (or<o:p></o:p></span></pre><pre><span lang=EN-GB>NULL) in one call.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>2) ecrt_master_sync_slave_clocks_diff()<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>Sets the masters application time and returns the time difference<o:p></o:p></span></pre><pre><span lang=EN-GB>between the last master app time and the last ref slaves time (in one<o:p></o:p></span></pre><pre><span lang=EN-GB>call).<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>This gets called instead of ecrt_master_application_time();<o:p></o:p></span></pre><pre><span lang=EN-GB>ecrt_master_sync_reference_clock(); and ecrt_master_sync_slave_clocks(),<o:p></o:p></span></pre><pre><span lang=EN-GB>although these calls still work in their current fashion.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>3) I have changed the ref_sync_datagram to 4 bytes instead of 8.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>From my reading of the ET1100 Hardware Data Sheet and looking at the<o:p></o:p></span></pre><pre><span lang=EN-GB>TwinCat datagrams the ref_sync_datagram should only sync the low 4 bytes<o:p></o:p></span></pre><pre><span lang=EN-GB>of the time.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>4) I have changed ec_master_find_dc_ref_clock() to use either the user<o:p></o:p></span></pre><pre><span lang=EN-GB>specified ref-slave (if found and compatible) or the first compatible<o:p></o:p></span></pre><pre><span lang=EN-GB>slave (if user ref slave not specified or not found or compatible).<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>5) I have changed ec_master_find_dc_ref_clock() to also update the<o:p></o:p></span></pre><pre><span lang=EN-GB>ref_sync_datagram with the ref slave address.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>Previously, if the first slave was not DC compatible (although unlikely)<o:p></o:p></span></pre><pre><span lang=EN-GB>then the ref_sync_datagram and sync_datagram would not refer to the same<o:p></o:p></span></pre><pre><span lang=EN-GB>slave and DC would fail to stay synced to the master.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>How I'm using it (Note: I'm using my rtdm versions):<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>1) During setup I'm calling ecrt_master_setup_distributed_clock() and<o:p></o:p></span></pre><pre><span lang=EN-GB>supplying my desired reference slave (via its slave_config).<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>2) During realtime operation, directly before calling<o:p></o:p></span></pre><pre><span lang=EN-GB>ecrt_rtdm_master_send() (to reduce timing jitter) I'm getting the system<o:p></o:p></span></pre><pre><span lang=EN-GB>time then calling ecrt_rtdm_master_sync_slave_clocks_diff() and caching<o:p></o:p></span></pre><pre><span lang=EN-GB>the returned time difference.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>3) After ecrt_rtdm_master_send() I'm using the cached time difference to<o:p></o:p></span></pre><pre><span lang=EN-GB>calculate a cycle period adjustment. I then use the cycle period<o:p></o:p></span></pre><pre><span lang=EN-GB>adjustment to set a system time offset every period. Whenever I read<o:p></o:p></span></pre><pre><span lang=EN-GB>the system time throughout the application I apply the system time<o:p></o:p></span></pre><pre><span lang=EN-GB>offset.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>Instead of using rtai's rt_wait_period I instead use rt_sleep_until<o:p></o:p></span></pre><pre><span lang=EN-GB>using the offset system time for the next wakeup time.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>I calculate my cycle period adjustment by averaging the time diff over<o:p></o:p></span></pre><pre><span lang=EN-GB>1000 periods. I've found any filter shorter than that gets too much<o:p></o:p></span></pre><pre><span lang=EN-GB>variation. I also add or subtract 1ns per period based on the current<o:p></o:p></span></pre><pre><span lang=EN-GB>cycles time diff to allow for any immediate variation requirements and<o:p></o:p></span></pre><pre><span lang=EN-GB>general drift.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>4) If I have multiple masters (which I currently don't) then the first<o:p></o:p></span></pre><pre><span lang=EN-GB>master will act this way and all subsequent masters will use the current<o:p></o:p></span></pre><pre><span lang=EN-GB>method (by sending the master time to the ref slave).<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>One thing to note is that the time difference returned by<o:p></o:p></span></pre><pre><span lang=EN-GB>ecrt_rtdm_master_sync_slave_clocks_diff() is often one period out. (ie<o:p></o:p></span></pre><pre><span lang=EN-GB>the time diff returned is ~1000000ns on a 1000000ns period.) The code<o:p></o:p></span></pre><pre><span lang=EN-GB>is:<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB> // adjust slave time back to send time (ie remove transmission delay)<o:p></o:p></span></pre><pre><span lang=EN-GB> uint32_t slaveTime = EC_READ_U32(master->sync_datagram.data) - <o:p></o:p></span></pre><pre><span lang=EN-GB> master->dc_ref_clock->transmission_delay;<o:p></o:p></span></pre><pre><span lang=EN-GB> uint32_t masterTime = (uint32_t)master->app_time;<o:p></o:p></span></pre><pre><span lang=EN-GB> <o:p></o:p></span></pre><pre><span lang=EN-GB> *time_diff = masterTime - slaveTime;<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB> // set new app time<o:p></o:p></span></pre><pre><span lang=EN-GB> ecrt_master_application_time(master, app_time);<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>This gets the time difference between the ref slaves time (adjusted for<o:p></o:p></span></pre><pre><span lang=EN-GB>transmission delay) from the returned sync datagram and the previous<o:p></o:p></span></pre><pre><span lang=EN-GB>master app time. It then sets the new master app time.<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>In my application I don't care if I'm one or more cycles out, I just<o:p></o:p></span></pre><pre><span lang=EN-GB>care that the cycles stay in sync. So I adjust my returned time diff to<o:p></o:p></span></pre><pre><span lang=EN-GB>the nearest cycle by:<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB> timeDiff = ((timeDiff + (scanTimeNS/2)) % scanTimeNS) -<o:p></o:p></span></pre><pre><span lang=EN-GB>(scanTimeNS/2);<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>Florian, a question for you, does this mean that the slaves might be<o:p></o:p></span></pre><pre><span lang=EN-GB>being set with a System Time Offset one period out? This could account<o:p></o:p></span></pre><pre><span lang=EN-GB>for why the "Slave did not sync after 5000 ms" error occurs now and<o:p></o:p></span></pre><pre><span lang=EN-GB>then. <o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>To calculate my calibrated cpu frequency to match the ref slaves clock I<o:p></o:p></span></pre><pre><span lang=EN-GB>record the system time from when I start to get time diffs. After some<o:p></o:p></span></pre><pre><span lang=EN-GB>time has passed I then perform the following calculation:<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB> int64_t diffTime = currentTime - startTime;<o:p></o:p></span></pre><pre><span lang=EN-GB> int64_t adjTime = diffTime + timeOffset;<o:p></o:p></span></pre><pre><span lang=EN-GB> int64_t cpufreq = nano2count(1000000000);<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB> cpu_freq = (int64_t)((double)cpufreq * (double)adjTime /<o:p></o:p></span></pre><pre><span lang=EN-GB>(double)diffTime);<o:p></o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB><o:p> </o:p></span></pre><pre><span lang=EN-GB>Regards,<o:p></o:p></span></pre><pre><span lang=EN-GB>Graeme.<o:p></o:p></span></pre><p class=MsoNormal><span lang=EN-GB><br><br><br><br><o:p></o:p></span></p><pre><span lang=EN-GB>_______________________________________________<o:p></o:p></span></pre><pre><span lang=EN-GB>etherlab-users mailing list<o:p></o:p></span></pre><pre><span lang=EN-GB><a href="mailto:etherlab-users@etherlab.org">etherlab-users@etherlab.org</a><o:p></o:p></span></pre><pre><span lang=EN-GB><a href="http://lists.etherlab.org/mailman/listinfo/etherlab-users">http://lists.etherlab.org/mailman/listinfo/etherlab-users</a><o:p></o:p></span></pre><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p></div></body></html>