# modbuv v0.1.0 - Table of Contents > A numeric function code-driven Modbus TCP Client/Server and RTU Master/Slave library for Elixir/OTP. ## Pages - [modbuv](readme.md) - [Changelog](changelog.md) - [LICENSE](license.md) ## Modules - [Modbuv.CRC](Modbuv.CRC.md): CRC16/MODBUS calculation. - [Modbuv.Codec](Modbuv.Codec.md): Modbus PDU encoding and decoding. A PDU is `<>`; slave/unit ids, CRC, and MBAP live in the transport layers. - [Modbuv.FcMap](Modbuv.FcMap.md): Server/Slave function-code registry: maps a numeric function code to the direction, data width, address region, and (for writes) single/multi layout. - [Modbuv.IEEE754](Modbuv.IEEE754.md): IEEE754 float helper. `:be` keeps the first register as the high word; `:le` swaps the two words. - [Modbuv.Model](Modbuv.Model.md): Pure functions over the Server/Slave DB: `%{slave_id => %{{region, address} => value}}`. - [Modbuv.Model.Shared](Modbuv.Model.Shared.md): Agent that holds the Server/Slave DB. - [Modbuv.Rtu](Modbuv.Rtu.md): Modbus RTU ADU framing: `<>`. - [Modbuv.Rtu.Framer](Modbuv.Rtu.Framer.md): Circuits.UART framer for Modbus RTU slave traffic. It accumulates bytes, derives the expected length from the fc_map, validates CRC, and resyncs byte-by-byte when a candidate is invalid. - [Modbuv.Rtu.Master](Modbuv.Rtu.Master.md): Modbus RTU master. Reads raw UART bytes and frames replies from the request currently in flight. Only one request may be in flight at a time. - [Modbuv.Rtu.Slave](Modbuv.Rtu.Slave.md): Modbus RTU slave. The UART runs with `Modbuv.Rtu.Framer` in active mode; complete frames are decoded, applied to the shared DB, and answered. - [Modbuv.Tcp](Modbuv.Tcp.md): Modbus TCP ADU framing: MBAP header plus the Codec PDU. - [Modbuv.Tcp.Client](Modbuv.Tcp.Client.md): Modbus TCP client. In passive mode `request/2` followed by `confirmation/1` returns the result synchronously; in active mode responses are sent to `d_pid` as `{:modbuv_tcp, frame, result}`. - [Modbuv.Tcp.Server](Modbuv.Tcp.Server.md): Modbus TCP server: listens on a port, serves each connection from the shared DB, and optionally notifies the owner of parsed requests. - [Modbuv.Telemetry](Modbuv.Telemetry.md): Telemetry instrumentation for `Modbuv.Tcp.Client` and `Modbuv.Rtu.Master` requests.