ad041 analog expansion resolution

[Bobodopalus 2]

hi everyone, ive recently started working at a company who uses omron PLC's im a bit more familiar with siemens i used in university.

 

one of my first tasks at work was to go through the current plc programs we have installed, ive noticed going through them that the previous engineer doesnt use the whole resolution of the analog input, i was wandering if this was some sort of practice im not familiar with or if they just have done it their own way.

for example the ad041 expansion unit has a resolution of 1/6000, which would be  scale of 0-1770 in hex, however in the programs im looking through this top end hex value is always listed as 1700.

 

im assuming there some safety precaution or something that i don't know about, thanks for any answers in advance

* the image is of the data points being put into the SCL function

 

[gtsuport 61]

Part number of the expansion unit?

[Bobodopalus 2]

ad041 analog input unit, attatched to a cp1l -m40 plc

[gtsuport 61]

I can understand your question.

At 1700h you are at 98% of resolution.  If you change this, it may affect other parts of the program.

Just make sure you understand everything that will be affected.

gtsuport

[IO_Rack 178]

I don't see any reason for it from the Omron side. It's possible it's specific to the connected device or they were calibrated as such. The scaling is straight forward and the CP1W-AD041 has over and under detection.

 

[gtsuport 61]

Also, looking at the values in the SCL instruction, your MAX scaled value is #64.  Not sure changing the #1700 to #1770 will make any difference.

And as IO Rack has said, it may be tied to the calibration of the input device.

[Bobodopalus 2]

i agree it wouldn't really make a difference, i guess it was either calibration or a mistake otherwise i dunno, thanks anyways

Edited 20 Feb 2020 by Bobodopalus