What Does Protocol Converter Mean?
In networking, a protocol converter is a device or program that converts from one protocol to another to allow interoperability between devices or systems that use incompatible protocols. Communication protocols are essentially the rules that define how the data passing through a device are to be processed and transmitted, so if two devices do not use the same protocol, then they would not be able to understand each other, hence the need for a protocol converter.
Techopedia Explains Protocol Converter
A protocol converter is designed to facilitate better communication between different devices from different vendors, most of which use different protocols, especially in the industrial sector where the communication protocols are often proprietary, which often results in vendor lock-in.
Protocol conversion can be done by computers through software provided that there is access to the data. For dedicated devices, however, that have no general-purpose OS like that used in a PC, they can handle the protocol they were designed for. They are thus incompatible with devices from other vendors. This is true for most networking protocols as different networks that use different media such as fiber use a different protocol (Fiber Channel Protocol) than Ethernet. Protocol conversion is usually done by the routers and switches themselves, but if that capability is not supported by the router, a separate protocol converter can be installed.
Most industrial equipment and even networking equipment make use of Ethernet cabling as well as RS-232 serial ports, so most protocol converters often have one or the other, or even both. There are some devices, however, that use a completely different connection port, so protocol converters meant for these devices either provide support for this port or include a port adapter.