Brainboxes: http://www.brainboxes.com/product/es-246/1-port-rs232-ethernet-to-serial-adapter
USR IoT: http://www.usriot.com
Moxa: http://www.moxa.com
Perle: https://www.perle.com/products/iolan-ds-terminal-server.shtml
Digi: https://www.digi.com
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