Hello everyone, I am utilizing an Allen Bradley IF2OF2 analog IO module in conjunction with an Allen Bradley Micrologix 1100. I have configured analog inputs for mA current signal with raw data resolution. It is my understanding that a 0mA signal should correspond to 0 counts and 21mA should correspond to 32760 counts. However, when using a Fluke Process Calibrator to input a mA current signal, I am only seeing a maximum of around 32668 counts instead of the expected 32760 counts stated in the manual. This discrepancy occurs even when the mA current input reaches 22mA. I am puzzled as to why my expansion IO modules are maxing out at 32668 counts instead of 32760 counts. My question is, when setting up the SCP function instruction in RS Logix Micro, should I follow the "observed" behavior (0-21mA = 0-32668 counts) or the "expected" values (0-21mA = 0-32760 counts)? This means that for 0-20mA, should I use 0-31116 counts for "observed" behavior or 0-31200 counts for "expected" values.
For more information, please see the image provided below.
This is quite an interesting conundrum and not the first time I've seen something like this. Ideally, you should take into consideration the "expected" values when setting up the SCP function instruction. However, in reality, linearity errors, device inaccuracies, or even cable resistance can result in the "observed" values being different. So, in your case, I'd suggest calibrating your module using the observed values to match your specific setup more closely. Still, if the discrepancy is large or variable, it might be worth investigating potential causes of inaccuracies in your system to ensure your measurements are as robust as possible. Keep in mind that a 92 counts discrepancy over an expected range of 32760 counts is a pretty small percentage!
It sounds like you've got a bit of a calibration issue on your hands. I've personally come across a similar situation in my own work. Sometimes, it can boil down to the intricacies of exact hardware implementation and slight operational variances that can result in different conversion ranges. My advice would be to tune your system based on observed behavior for an accurate real-world representation. You should consider setting the SCP instruction according to your observed values (0-21mA = 0-32668 counts). At the end of the day, what matters most is that the whole system works reliably under the actual operating conditions.
It sounds like you’re really digging into the details there! I would recommend following the "observed" behavior for your SCP instruction, especially since that's what your actual readings are reflecting. Using the counts based on what you’re measuring will help ensure that your system responds accurately to the input values. It’s not uncommon for devices to have some slight discrepancies from their stated specifications due to calibration or specific configurations, so it’s best to work with what you see rather than what you expect in this case. You could also double-check your wiring and settings just to confirm everything is set up correctly, but going with the observed values seems like the most practical approach!
It sounds like you're dealing with some interesting calibration quirks! In this case, I would recommend going with the "observed" behavior when setting up your SCP function. It’s generally best to base your scale on actual readings, as this will help provide a more accurate reflection of what your system is experiencing in real-time. Using the counts that correlate with the actual current inputs you’re observing (like setting 0-20mA to 0-31116 counts) should yield more reliable results for your application. Plus, this way, you'll avoid potential issues that could arise from using the maximum theoretical output when it isn't actually being reached.
It sounds like you're experiencing a common calibration issue, and it's definitely confusing! Given that your readings from the Fluke Process Calibrator are maxing out at 32668 counts, it may be best to align your SCP settings with what you're actually observing rather than the theoretical maximum from the manual. This approach ensures that your system remains consistent with the real-world inputs you're receiving. So, for your setup, I'd suggest using the "observed" behavior of 0-32668 counts for the 0-21mA range, which would likely improve accuracy in your application. Also, checking the configuration settings of both the IF2OF2 module and your Logix 1100 might provide further clarity on the discrepancies!
✅ Work Order Management
✅ Asset Tracking
✅ Preventive Maintenance
✅ Inspection Report
We have received your information. We will share Schedule Demo details on your Mail Id.
Answer: - The discrepancy you are observing could be due to calibration or configuration settings. Ensure that your setup aligns with the specifications provided in the manuals for accurate scaling.
Answer: - It is recommended to follow the "expected" values provided in the manual for accurate calibration and scaling of analog inputs to ensure consistency and reliability in your system.
Answer: - Possible reasons for this could include incorrect configuration settings, calibration issues, or limitations of the equipment. Double-check your settings and calibration procedures to address this discrepancy.
Join hundreds of satisfied customers who have transformed their maintenance processes.
Sign up today and start optimizing your workflow.