modelUartEchoDevice
Serial echo device: sends back every received byte unchanged
Extends from Internal.Devices.PartialUartDevice (Base of the external serial devices: electrical link, decoding, two transmission modes, quantities exchanged with the model).
Information
The simplest of the devices derived from Internal.Devices.PartialUartDevice: it only overrides three Booleans. Each decoded byte is immediately put back into the transmit queue, without waiting for the end of the line — hence without any notion of command or delimiter.
Its interest is to be a real partner on the link: it replaces the loopback of Examples.Uart.Loopback, which only existed to work around an alias merge between two pins of the same MCU. Here the two ends are two distinct components, and the link is a simple wire.
Each byte goes back with a delay of about one frame, since it must have been fully decoded (up to the stop bit) before it can be sent again — exactly like a real repeater. It is also the component of choice to validate a communication chain before connecting the final device to it.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Electrical › Supply | |||
| Boolean | useSupplyPin (from PartialSupplyPin) | false | Show the VCC supply pin: the peripheral is supplied by the circuit (its high levels follow VCC, its consumption IQ is drawn from VCC) - unchecked: ideal internal supply VOH, nothing to wire |
| Modelica.Units.SI.Voltage | VOH (from PartialSupplyPin) | Interfaces.VOH | Logic high voltage: ideal internal supply, high level of the outputs and of the pull-ups - with the VCC pin, the voltage of VCC is used instead |
| Modelica.Units.SI.Current | IQ (from PartialSupplyPin) | 1e-3 | Current drawn from VCC by the peripheral (quiescent consumption, outputs excluded) |
| Boolean | useGroundPin (from PartialSupplyPin) | true | Show the GND pin - unchecked: the peripheral is referenced to the simulation ground (0 V), nothing to wire |
| Electrical › Levels | |||
| Modelica.Units.SI.Voltage | VOL (from PartialUartPins) | Interfaces.VOL | Logic low voltage |
| Modelica.Units.SI.Voltage | VIH (from PartialUartPins) | Interfaces.VIH | Threshold above which an input reads high |
| Modelica.Units.SI.Voltage | VIL (from PartialUartPins) | Interfaces.VIL | Threshold below which an input reads low |
| Electrical › Impedances | |||
| Modelica.Units.SI.Resistance | ROut (from PartialUartPins) | Interfaces.ROut | Output series resistance |
| Modelica.Units.SI.Resistance | RPullUp (from PartialUartPins) | 1e6 | Pull-up of the RX input to the supply |
| Electrical › Pins | |||
| Boolean | useTxPin (from PartialUartPins) | true | Show the TX pin - unchecked for a device that never transmits (its output stage then stays unconnected) |
| Behaviour | |||
| Interfaces.UartBehaviour | behaviour (from PartialUartDevice) | Interfaces.UartBehaviour.Table | Origin of the behaviour: command table or Python script |
| String | scriptPath (from PartialUartDevice) | "" | Script .py describing the behaviour of the device (Script mode) |
| Serial link | |||
| Integer | baudrate (from PartialUartDevice) | 1200 | Link speed, in baud |
| Integer | dataBits (from PartialUartDevice) | 8 | Number of data bits of a frame (5 to 8, as machine.UART bits=) |
| Interfaces.UartParity | parity (from PartialUartDevice) | Interfaces.UartParity.None | Parity of a frame (as machine.UART parity=: None, 0 = even, 1 = odd) |
| Integer | stopBits (from PartialUartDevice) | 1 | Number of stop bits (1 or 2, as machine.UART stop=) |
| String | terminator (from PartialUartDevice) | "\n" | Character marking the end of a received command (only the first character is kept) |
| Simulation | |||
| Modelica.Units.SI.Time | tickPeriod (from PartialUartDevice) | 0.1 | Period of the minimal sync point: a safety net, the actual pace comes from the engine's deadlines |
| Table › Request / response | |||
| Boolean | respondEnabled (from PartialUartDevice) | true | Reply to the recognised commands |
| String | commandTable (from PartialUartDevice) | "" | Table "CMD=>REPLY|CMD=>REPLY"; "|" and "=>" are reserved. {vN} inserts valueIn[N] into the reply, {oN} captures a number of the command into valueOut[N] |
| Modelica.Units.SI.Time | responseDelay (from PartialUartDevice) | 0.002 | Delay between the recognition of a command and the start of the reply |
| Boolean | echoEnabled (from PartialUartDevice) | false | Send back every received byte unchanged |
| Table › Periodic transmission | |||
| Boolean | periodicEnabled (from PartialUartDevice) | false | Transmit spontaneously, without being asked |
| Modelica.Units.SI.Time | period (from PartialUartDevice) | 1 | Period of the spontaneous transmission (in Script mode: call period of on_tick) |
| String | periodicTemplate (from PartialUartDevice) | "" | Template of the periodically transmitted frame ({vN} inserts valueIn[N]) |
| Inputs / outputs › Inputs ({vN}, inserted into transmitted frames) | |||
| Boolean | useValueInput (from PartialUartDevice) | false | Take the quantities from the valueIn connector rather than from a constant |
| Integer | nIn (from PartialUartDevice) | 1 | Number of quantities received from the model |
| Real | fixedValue (from PartialUartDevice) | 0 | Value used when valueIn is not connected |
| Inputs / outputs › Outputs ({oN}, captured from received frames) | |||
| Boolean | useValueOutput (from PartialUartDevice) | true | Show the valueOut connector - unchecked for a device that returns nothing to the model |
| Integer | nOut (from PartialUartDevice) | 1 | Number of quantities returned to the model - leave the connector unconnected if unused |
| Real | valueOutStart (from PartialUartDevice) | 0 | Value of valueOut before any capture |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Electrical.Analog.Interfaces.NegativePin | GND (from PartialSupplyPin) | Common reference (ground), to be connected to the microcontroller's one - shown when useGroundPin is checked | |
| Modelica.Electrical.Analog.Interfaces.PositivePin | VCC (from PartialSupplyPin) | Supply of the peripheral (e.g. 3V3(OUT) of a Raspberry Pi Pico) - shown when useSupplyPin is checked | |
| Modelica.Electrical.Analog.Interfaces.PositivePin | TX (from PartialUartPins) | Transmission of the device - to be connected to the receive pin of the microcontroller - shown when useTxPin is checked | |
| Modelica.Electrical.Analog.Interfaces.PositivePin | RX (from PartialUartPins) | Reception of the device - to be connected to the transmit pin of the microcontroller | |
| Modelica.Blocks.Interfaces.RealInput[nIn] | valueIn (from PartialUartDevice) | Quantities supplied by the model, inserted into the transmitted frames by {v1}..{vN} | |
| Modelica.Blocks.Interfaces.RealOutput[nOut] | valueOut (from PartialUartDevice) | Quantities extracted from the received frames by {o1}..{oN} - the device then becomes an actuator |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | txActive (from PartialUartDevice) | A frame is being transmitted | |
| Boolean | rxBusy (from PartialUartDevice) | A frame is being received | |
| String | lastRx (from PartialUartDevice) | Last complete line received | |
| String | lastTx (from PartialUartDevice) | Last payload transmitted |