As we talked about, since the IP address was set using the AB Configuration Manager, those settings take precedence over the ethcfg.cfg file. The IPConfig tool just changes that file so you will need the DB9 to RJ11 serial cable that came with the device. You will want to first upload the config from the device, then change the network settings and download it back to the device.
Here is a link to the IP address configuration instructions for future reference:
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