help configuring logo

[wayneplc 0]

Any help suggestions welcome. Continuation from earlier post regarding logo and application as part of level sensing device. I was told it could'nt be done but it is actually quite easy . Ill give a review of the problem. It is required to connect a level sensing device to a logo . The output of the device is an analog signal (voltage) 0.3-4.5V . From my investigations the logo has analog inputs and in function block diagram programming there are blocks which enable reading in the analog signal amplifying the analog signal and a message block function which can output the configured analog signal . My question does anyone out there know how to parametrize the blocks

[Rod_Hackney 2]

Please see the text below, it is an piece of a siemens article about scaling analogs on a logo. The following sample calculation demonstrates the scaling of analog measured values in LOGO! Soft Comfort. A weighing module with a range of 0kg to 10kg provides the weighing range as a proportional voltage of 0.5V to 4.7V. The following parameters must be specified for correct processing of these values in LOGO!: Gain Offset To give a clear definition of these parameters the measuring voltage put on the X axis and the weight to be measured on the Y axis of a Cartesian coordinate system. The two known points (0.5V/0kg) and (4.7V/10kg) were entered as a cross and joined with a straight line. The "Gain" parameter is calculated from the gradient of the straight lines: Gain = weighing range / measuring range = (max. weighing value - min. weighing value) / (maximum measured value - minimum measured value) The result for the present example is: Gain = ((10kg - 0kg) / (4.7V -0.5V) = 2.38 kg/V Assuming that the minimum measured value is a weight of 0kg, the offset is calculated as follows: Offset = Gain * Minimum measured value The result for the present example is: Offset = 2.38kg/V * (-0.5V) = -1.19kg Enter the value 2.38 for the "Gain" parameter in the appropriate dialog field of the analog amplifier. The offset can only be given as an integer. The value of "-1.19kg" calculated in the example above has to be multiplied by a factor of 100. The offset is then "-119 kg" which you enter in the appropriate field of the analog amplifier dialog. In order to be able to display the values in "kg" you specify "2" for "Decimals in the message text". The parameters "Minimum" and "Maximum" are calculated automatically by LOGO! Comfort.

[wayneplc 0]

Thanks for your help I visited the siemens forum and got further help today I tried connecting the logo but didnt understand how to connect to the analog inputs.Do I7 and I8 have to be configured as AI1 and AI2 so they can be used as analog inputs or do they function as such automatically when an analog signal is connected . I tried reading the manual but the explanation is not clear[

[Crossbow 295]

You should not have to configure anything to use the last 2 inputs as analog. Just attach them to analog instructions as far as I remember. Keep in mind the last 2 as analog only works on DC powered DC input units. AC Logos require analog modules.