X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 02 May 2014 07:28:33 -0400 Message-ID: X-Original-Return-Path: Received: from vms173003pub.verizon.net ([206.46.173.3] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTP id 6855396 for lml@lancaironline.net; Thu, 01 May 2014 22:47:16 -0400 Received-SPF: pass receiver=logan.com; client-ip=206.46.173.3; envelope-from=lancair403@verizon.net Received: from self87aab97f5d ([unknown] [71.176.56.193]) by vms173003.mailsrvcs.net (Sun Java(tm) System Messaging Server 7u2-7.02 32bit (built Apr 16 2009)) with ESMTPA id <0N4X003TUEDJSYI0@vms173003.mailsrvcs.net> for lml@lancaironline.net; Thu, 01 May 2014 21:46:33 -0500 (CDT) X-Original-Message-id: <017CC5A3FBF748F798F0CD2564A8BD5E@self87aab97f5d> From: "William Rumburg" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: VMS1000 pressure gauges on LNC2 X-Original-Date: Thu, 01 May 2014 22:46:28 -0400 MIME-version: 1.0 Content-type: multipart/alternative; boundary="----=_NextPart_000_00A6_01CF658F.307DC030" X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 This is a multi-part message in MIME format. ------=_NextPart_000_00A6_01CF658F.307DC030 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Nick - My approach was to search for a transducer with the same electrical = parameters as the MediaMate, for which the VMS1000 fuel and oil pressure = indications were designed (i.e. 5VDC excitation and 50mV full-scale = output). Unfortunately, that turns out to be a combination rarely used = in industry; however, one version of the MSP US300 series has those = parameters, which makes it an exact electrical replacement. Furthermore, = MSP transducers are modern, high-quality and inexpensive - in contrast = with the antiquated, failure-prone and outrageously overpriced = MediaMate. I appreciate your efforts toward another solution, but why = not go with the US321??? Bill Rumburg =20 ----- Original Message -----=20 From: Nick Long=20 To: lml@lancaironline.net=20 Sent: Tuesday, April 29, 2014 12:46 PM Subject: [LML] Re: VMS1000 pressure gauges on LNC2 Hi Bill, (Bill Rumburg, that is; there are two Bills in the thread) I don=E2=80=99t disagree with anything you said. But the fact that the = VMS-1000 DPU could be difficult to keep going in the long term =E2=80=93 = liable to become toast as you say =E2=80=93 makes me reluctant to go for = sensors that are specific to it. If my scheme works then I have pressure = sensors that might (not guaranteed, but might) work with another display = system. At least they will be industry standard and I=E2=80=99m also = going to use industry standard connectors, not the spade terminals. If the fuel flow sensor failed, then I would probably ignore it, at = least for a while. But without OP and FP displays, you have to take = action immediately. Yours, Nick From: William Rumburg=20 Sent: Tuesday, April 29, 2014 1:13 PM To: lml@lancaironline.net=20 Subject: [LML] Re: VMS1000 pressure gauges on LNC2 Nick - The VMS-1000 was a state-of-the-art engine indication/fuel management = system back in the mid-90's and is still quite respectable. However, = it's DPU is comprised of individual electronic devices which are now = obsolete; hence, if any one of them is damaged or fails, you may as well = consider the entire DPU toast. The possiblity of damage to an individual = component is my reason for not experimenting with voltage dividers, etc. = in an attempt to make non-standard sensors work. Fortunately, sensors = are -for the most part- still available. One insurmountable problem, = however, would be replacement of the fuel flow sensor. FloScan went from = an 18K to a 6K unit and fuel flow accuracy requires that sensors "K" = factor be programmed into the DPU, which is no longer possible for the = VMS. The MediaMate's terminals are numbered 1 thru 4 and function as you've = listed; however, terminals 2 and 4 are more correctly identified as - = and + 5 VDC excitaton, with terminals 1 and 3 as + and - mV signal. I've = also failed to mention that the MediaMate's plug-on 'Hirschmann' = terminals are ill-conceived and problem-prone, especially for a mV = signal; whereas, the MSP US 300 series all have a permanent, = factory-installed connection. Bill ------=_NextPart_000_00A6_01CF658F.307DC030 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Nick -
 
My approach was to search for a = transducer=20 with the same electrical parameters as the MediaMate, for which the = VMS1000 fuel=20 and oil pressure indications were designed (i.e. 5VDC excitation = and 50mV=20 full-scale output). Unfortunately, that turns out to be = a combination=20 rarely used in industry; however, one version of the MSP US300 = series=20 has those parameters, which makes it an exact electrical replacement.=20 Furthermore, MSP transducers are modern, high-quality and = inexpensive - in=20 contrast with the antiquated, failure-prone and outrageously overpriced=20 MediaMate. I appreciate your = efforts toward=20 another solution, but why not go with the US321???
 
Bill Rumburg
  
 
----- Original Message -----
From:=20 Nick Long=20
Sent: Tuesday, April 29, 2014 = 12:46=20 PM
Subject: [LML] Re: VMS1000 = pressure=20 gauges on LNC2

Hi Bill,
 
(Bill Rumburg, that is; there are two Bills in the thread)
 
I don=E2=80=99t disagree with anything you said. But the fact = that the VMS-1000=20 DPU could be difficult to keep going in the long term =E2=80=93 liable = to become toast=20 as you say =E2=80=93 makes me reluctant to go for sensors that are = specific to it. If=20 my scheme works then I have pressure sensors that might (not = guaranteed, but=20 might) work with another display system. At least they will be = industry=20 standard and I=E2=80=99m also going to use industry standard = connectors, not the spade=20 terminals.
 
If the fuel flow sensor failed, then I would probably ignore it, = at least=20 for a while. But without OP and FP displays, you have to take action=20 immediately.
 
Yours,
 
Nick
 
 
Sent: Tuesday, April 29, 2014 1:13 PM
Subject: [LML] Re: VMS1000 pressure gauges on=20 LNC2
 
Nick -
 
The VMS-1000 was a state-of-the-art = engine=20 indication/fuel management system back in the mid-90's and is still = quite=20 respectable. However, it's DPU is comprised of individual = electronic devices which are now obsolete; hence, if any = one of them=20 is damaged or fails, you may as well consider the entire DPU toast. = The=20 possiblity of damage to an individual component is my reason for not=20 experimenting with voltage dividers, etc. in an attempt to make = non-standard=20 sensors work. Fortunately, sensors are -for the most part- still = available.=20 One insurmountable problem, however, would be replacement of the fuel = flow=20 sensor. FloScan went from an 18K to a 6K unit and fuel flow accuracy = requires=20 that sensors "K" factor be programmed into the DPU, which is no longer = possible for the VMS.
The MediaMate's terminals are = numbered 1 thru 4=20 and function as you've listed; however, terminals 2 and 4 are more = correctly=20 identified as - and + 5 VDC excitaton, with terminals 1 and 3 as + and = - mV=20 signal. I've also failed to mention that the MediaMate's plug-on = 'Hirschmann'=20 terminals are ill-conceived and problem-prone, especially for a mV = signal;=20 whereas, the MSP US 300 series all have a permanent, factory-installed = connection.
 
Bill
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