DT50 to AI on ET200SP, PLC S7-1517 - improve positioning accuracy?

Hello Vishakha,

I'm currently using DT50 on some of my equipment. I use it for positioning but the accuracy is not good enough (+-1mm noise because of analog signal). I wonder if switching to IO link improves this accuracy?

If not I'll have to revamp the system to have encoder in combination with drive-cliq to position the equipment.

Current setup:

DT50 to AI on ET200SP, PLC S7-1517 reads AI signal and sends speed setpoint to drive.

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Split from ET200 ECO PN IO link module with Sick Distance sensor.

If your position feedback analog signal is noisy, what do you imagine is happening to every other analog signal?

If you have 3-wire analog devices, you may need galvanic isolators (signal conditioners), and may even need to up-size the 0V wire to all your 0V distribution terminal groups, and especially any that run between the voltage source and any remote IO panels.  I found great improvements by increasing the 0V wire size by 2 standard sizes when I use 3-wire analog devices.

If you can use 0-20 or 4-20mA analog signals, you are much better off.  Even if the analog input is voltage, you can insert the proper resistor at the input terminals to get proper and less noisy analog inputs.

I guess what I'm saying is, you can use the IO link as your "galvanic isolator", which is a lot of effort to disguise a system-wide problem for a single input.

MatthiasDemaret

Hello Vishakha,

I'm currently using DT50 on some of my equipment. I use it for positioning but the accuracy is not good enough (+-1mm noise because of analog signal). I wonder if switching to IO link improves this accuracy?

If not I'll have to revamp the system to have encoder in combination with drive-cliq to position the equipment.

Current setup:

DT50 to AI on ET200SP, PLC S7-1517 reads AI signal and sends speed setpoint to drive.

------------------------------------------------------------------------------------------
Split from ET200 ECO PN IO link module with Sick Distance sensor.

Hi,

Thanks for this detailed explination, currently we aren't using that much AI on this equipment. This is the only AI that needs to be pretty accurate. That's why I think about switching to IO link. I have no idea how 'noisy' the other Ai's are. I've also contacted the supplier of the sick DT50 and he says that the lack of repeatability of the device is because of the analog signal. I look into the IO link module and look what it does to the accuracy.

Kind regards, this topic can be closed.

Matthias