# Communication

- [NPN Output](/qr/fu-lt-english-v1/communication/npn-output.md)
- [Analog Output 4-20mA](/qr/fu-lt-english-v1/communication/analog-output-4-20ma.md)
- [RS485  Modbus RTU](/qr/fu-lt-english-v1/communication/rs485-modbus-rtu.md)
- [Modbus RTU Protocol](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol.md)
- [Read-Only Memory (ROM)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-only-memory-rom.md)
- [Read-Only Memory (ROM) – List](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-only-memory-rom/read-only-memory-rom-list.md)
- [Read-Only Memory – Read Command (04)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-only-memory-rom/read-only-memory-read-command-04.md)
- [Read/Write Memory (RAM)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram.md)
- [Read/Write Memory – Read List](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram/read-write-memory-read-list.md)
- [Read/Write Memory – Read Command (03)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram/read-write-memory-read-command-03.md)
- [Read/Write Memory – Single Register Write Command (06)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram/read-write-memory-single-register-write-command-06.md)
- [Read/Write Memory – Dual Register Write Command (30)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram/read-write-memory-dual-register-write-command-30.md)
- [Read/Write Memory – Four Register Write Command (31)](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram/read-write-memory-four-register-write-command-31.md)
- [Single Bit Data Read/Write Commands (01 / 05) – Common for HMI](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/single-bit-data-read-write-commands-01-05-common-for-hmi.md)