Analog 1762-of4 Ml1100

[Happeeman]

Hello,

I'm new to analog signals as far as scaling them and what the useable output voltage will be. I need to utilize the 0-10vdc output. I have a value from n11:0 that ranges in integers from 0 -60. I would like 0-60 to represent 0-60hz on the vfd Im trying to control. I understand how to use the scp instruction somewhat but I want the scale to be for instance:

n:11 = 45 so output voltage to 7.5 vdc

Im totally missing something. Why doesnt the analog output address like decimals so I can get finer control instead of increasing the integer value without any output movement?

If you couldn't tell I really need the help.

Dave

 

[OZEE]

Full scale output on an analog output (or input) is NOT the range that you define, but the range defined by the manufacturer. I don't have the manuals for the ML1100 with me right now, but I would guess that 0-10VDC is represented by 0-32767. Therefore, 7.5vdc would be 24575 (32767*7.5/10)

 

[consys]

Somewhere in your documentation it will state that your particular analog output card is either 12, 13, 14, 15 or 16 bit resolution. 12 bit resolution equates to a range of 0 to 4095. where a count of 0 = 0 volts and 4095 = 10 Volts. You would then use SCP to scale the your n11:0 so that
N11:0 (min) = 0. N11:0 (max) = 60
and your Output word min = 0 , your Output word max. = 4095.
of course this will only give you 60 steps between min and max. You could also range your N11:0 in tenths of a hertz so that your max. value would be 600 and this would represent 60.0 hertz adjust the parameters on your SCP accordingly and you would then have 600 steps between min and max.

 

[Mickey]

See Pic below.
Just scale your analog output word to Raw/proportional 0-32760
and you should not have a problem getting the resolution you require.

 

[Happeeman]

VB to OPC to 1762-of4

Thank-you guys. I got the solution before I applied the walk away and come back to it method. Yeah that is great info. I was just very discoursged tring to find any manuals at AB. Here's one though. My GUI is a VB application driven by OPC. How can I increase the reaction time of my VB slider to the output?

 

[Mickey]

Update on 1762-OF4 data format.

 

[consys]

The OPC Server is responsible for reading the data and publishing it to it's clients. Have a look thru the OPC server options to see how it reacts to Analog values, typically they (OPC server) only react to a change, it may be that the OPC server needs to see a change of a certain magnitude before it publishes an updated value to it's clients. It may also have a time setting where even if the value doesn't change it will re-publish.