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Carl

Member Since 30 May 2005
Offline Last Active Dec 31 2008 06:16 AM
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Posts I've Made

In Topic: Modbus Rtu And Danfoss Fc202

21 July 2008 - 01:26 PM

that sounds like a decimal addressing range..........it sounds like you should be using a hex range which is basically a function code and then a 8 bit hi and 8 bit low ....try that modmat software I'm sure that in a hex format....

In Topic: Modbus Rtu And Danfoss Fc202

17 July 2008 - 07:07 AM

QUOTE (marke @ Jul 15 2008, 07:33 PM) <{POST_SNAPBACK}>
Hi

I have a project requiring serial coms control and monitoring of a Danfoss FC202 using MODBUS RTU.

I have the PLC talking, but can not work out how to access the current readings etc as these are on parameters that can not be mapped into the MODBUS register set.
The parameters below 9.99 map into 40000 - 49999, but how do you access parameters 10.00 and above??
I must be missing something.

Best regards,
Mark

I recently finished a project on modbus I have a pdf files that could possibly help you ....how do I get them to you?

In Topic: Vfd Failure

31 March 2008 - 03:16 PM

it could cause problems if you are switching the drive on and off via the mains contactor as a stop start thats if the duty cycle of the on off is very short..............I've seen this problem on the old mitsi drives ....it used to burn out the surge resistor.....and then in turn it would weld the surge contactor........and then it would pop the input bridge due to the repeatd high inrush current.....and if you where really unlucky it would feed AC to the capacitor bank....the caps would then explode.............fortuanatly I've only seen one catch on fire and that was on a work bench.......mind you the ringing in my ears lastd about an hour and my boss was not to pleased

its called........... learning the hard way

In Topic: P I For The Drives

26 March 2008 - 04:02 PM

try this site:
http://www.embedded....0/0010feat3.htm

In Topic: Vfd Failure

21 March 2008 - 10:06 AM

It is usual practice to keep the power and control cable separate as this reduces the likely hood of interference from the power cable…….as this can inductively couple……..especially in inverters as you have a rapidly changing signal on the leading and trailing edge of the output waveform to the motor……… if memory serves me correctly a square a wave is rich in odd harmonics.

sorry I should have mentioned that cables running in parallel have a greater likely hood of causing interference……..basically it is a transformer in a straight line