I have problem with Digi One IAP with RS-485, 4 wires, using Kepware

Today the converter is working smoothly for 2-4 months and then freezes, which is done is remove the power and again energized, and immediately returned to work correctly.

The OPC is that I’m using Kepware and the converter is set according to a manual that is under the page of this software manufacturer.

I need your support, because the data are monitored by this converter are critical to the customer.