Comments on: Maplin N56FU Digital Multimeter http://www.thebits.info/general/n56fu-172.htm Not your everyday tech journal Thu, 26 Aug 2010 11:35:44 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Clive Harris http://www.thebits.info/general/n56fu-172.htm/comment-page-1#comment-5940 Clive Harris Thu, 26 Aug 2010 11:35:44 +0000 http://www.thebits.info/?p=172#comment-5940 The screen light bug can be avoided if the light is turned off manually (press Hold/Light button for > 2 seconds) before the light times off (10 seconds). Once the light has timed off automatically, a subsequent press of any button is likely to initiate the bug causing a high current (>40mA) draw from the 9V battery. Once started, the high current draw continues until the function switch is moved to OFF; whether or not the lamp is on. When employing the manual light switch off workaround, the meter uses about 10mA when the light is on, and 4mA when the light is off. The screen light bug can be avoided if the light is turned off manually (press Hold/Light button for > 2 seconds) before the light times off (10 seconds). Once the light has timed off automatically, a subsequent press of any button is likely to initiate the bug causing a high current (>40mA) draw from the 9V battery. Once started, the high current draw continues until the function switch is moved to OFF; whether or not the lamp is on. When employing the manual light switch off workaround, the meter uses about 10mA when the light is on, and 4mA when the light is off.

]]> By: Lord TCT http://www.thebits.info/general/n56fu-172.htm/comment-page-1#comment-5939 Lord TCT Wed, 25 Aug 2010 16:05:40 +0000 http://www.thebits.info/?p=172#comment-5939 Thanks for the tips Clive! It should also be noted that the screen light is very power hungry - draining a carbon-zinc battery in just 5 hours on! I think I'll be replacing the white-ish LEDs with more power friendly yellow LEDs! Thanks for the tips Clive! It should also be noted that the screen light is very power hungry – draining a carbon-zinc battery in just 5 hours on! I think I’ll be replacing the white-ish LEDs with more power friendly yellow LEDs!

]]> By: Clive Harris http://www.thebits.info/general/n56fu-172.htm/comment-page-1#comment-5936 Clive Harris Mon, 23 Aug 2010 16:41:09 +0000 http://www.thebits.info/?p=172#comment-5936 Thanks for posting your article and the links. They provide fascinating insights to the innards of this remarkable meter. Through use, I've found that the N56FU has a bug which can rapidly discharge the meter's internal 9V battery. When measuring with the meter, if you use the screen light, then wait for the light to time off, then press max/min (twice if max/min not previously pressed), the meter draws more than 40mA from its internal 9V battery. The only way I've found to stop this high current drain is to move the function switch to OFF. Thanks for posting your article and the links. They provide fascinating insights to the innards of this remarkable meter.

Through use, I’ve found that the N56FU has a bug which can rapidly discharge the meter’s internal 9V battery. When measuring with the meter, if you use the screen light, then wait for the light to time off, then press max/min (twice if max/min not previously pressed), the meter draws more than 40mA from its internal 9V battery. The only way I’ve found to stop this high current drain is to move the function switch to OFF.

]]> By: Dave Kent http://www.thebits.info/general/n56fu-172.htm/comment-page-1#comment-5928 Dave Kent Tue, 17 Aug 2010 16:34:28 +0000 http://www.thebits.info/?p=172#comment-5928 Crash Override - Thanks very much! It works. Now I know what I'm supposed to do, I lookedf at page 9 of the instruction booklet where it states . . . Pressing and holding this button for about 2 seconds sets the meter to USB communication mode . . . ! I was initially thrown by page 33 which says that there are instructions on the CD (which there aren't!) Again - thank you! Thanks again Lord TCT for pointing me at updated software! Crash Override – Thanks very much! It works. Now I know what I’m supposed to do, I lookedf at page 9 of the instruction booklet where it states . . . Pressing and holding this button for about 2 seconds sets the meter to USB communication mode . . . ! I was initially thrown by page 33 which says that there are instructions on the CD (which there aren’t!)
Again – thank you!

Thanks again Lord TCT for pointing me at updated software!

]]> By: Lord TCT http://www.thebits.info/general/n56fu-172.htm/comment-page-1#comment-5924 Lord TCT Mon, 16 Aug 2010 09:48:20 +0000 http://www.thebits.info/?p=172#comment-5924 Daniel, I wrote my own RS232 wrapper using C# (Microsoft .NET) for multiplexing. It's pretty simple. For starters, you may want to try using WinForm's the Serial Port component to interface with your meters and once you are able to read the meter's sentences, you should refer to the manual below on how to interpret them: http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf You're gonna have to code your own data logger and visualiser of course, but .NET 4.0 has a pretty useful X-Y scatter chart component built in. Daniel,

I wrote my own RS232 wrapper using C# (Microsoft .NET) for multiplexing. It’s pretty simple. For starters, you may want to try using WinForm’s the Serial Port component to interface with your meters and once you are able to read the meter’s sentences, you should refer to the manual below on how to interpret them:

http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf

You’re gonna have to code your own data logger and visualiser of course, but .NET 4.0 has a pretty useful X-Y scatter chart component built in.

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