Hilscher India Pvt. Ltd. Manufactures RS 422/485 Potential Free Serial Interface Real Time Ethernet Gateways. Hilscher India Pvt. Ltd is an ISO 9001 company. RS 422/485 Potential Free Serial Interface Real Time Ethernet Gateways has purpose of the field bus Master-LINK interface for the connection of exactly one Slave field device to the netTAP. RS 422/485 Potential Free Serial Interface Real Time Ethernet Gateways of model number NT 40-EN-RSI4\CCE with serial interface at the front of the housing is always provided as a potential-free RS-232 / 422 / 485 and is always arranged via the configurator.