From 69585a963bdebb469a2910137892f524ff541676 Mon Sep 17 00:00:00 2001 From: Martino Ferrari Date: Sun, 1 Nov 2026 07:48:20 +0100 Subject: [PATCH] spec: MCC E-1608 source plugin (sub-project 3) --- .../specs/2026-10-31-e1608-source-design.md | 153 ++++++++++++++++++ 1 file changed, 153 insertions(+) create mode 100644 docs/superpowers/specs/2026-10-31-e1608-source-design.md diff --git a/docs/superpowers/specs/2026-10-31-e1608-source-design.md b/docs/superpowers/specs/2026-10-31-e1608-source-design.md new file mode 100644 index 0000000..cdac441 --- /dev/null +++ b/docs/superpowers/specs/2026-10-31-e1608-source-design.md @@ -0,0 +1,153 @@ +# MCC E-1608 source plugin (sub-project 3 of 4) + +Date: 2026-10-31 +Branch: `feature/source-e1608` (from `feature/source-plugins`, sub-project 1) + +## Context + +Sub-project 1 added the `DataSource` / `SourceKind` / `SourceRegistry` framework and ported +UDPS onto it. This sub-project adds a second kind, `e1608`: the Measurement Computing E-1608 +Ethernet DAQ (8 SE / 4 DIFF 16-bit analog inputs, 2 analog outputs, 8 DIO bits, one 32-bit +counter), with its own connect form and two side-stack panels. + +References for the wire protocol, both written by the user: + +- Primary: `~/Projects/marte2_projects/MCC_E1608_DataSource`, a MARTe2 DataSource + (`E1608DataSource.{h,cpp}`, `E1608ScanFifo`). Its class comment in the header is the + authoritative list of parameters and behaviour. It is bound to MARTe2 (`BasicTCPSocket`, + `StreamString`, `SingleThreadService`), so it is **ported** to plain C++, not linked. +- Cross-check: `~/Projects/uopi/internal/datasource/mcc/{protocol,e1608}.go`, an independent + Go implementation of the same protocol. + +No board is available. The mock is the only verification until one is attached. + +## Decisions + +| Question | Decision | +| --- | --- | +| DAC / generator | Static level plus a software waveform (sine, square, triangle, ramp), 10 Hz at most. Runs as a timer inside `poll()`; no extra thread. | +| Hardware | None available. A protocol mock (`tools/mock_e1608.py`) is the contract. Commands whose layout rests on a single reference (or where the two disagree) are listed as unverified. | +| Analog input config | Full: per-channel enable and range, global SE/DIFF, MAC discovery, external clock, trigger, DI/counter poll rate. | +| Digital lines and counter | Plot channels the user chooses, off by default, enabled per line in the connect form. | +| Acquisition modes | Hardware-paced only (scan rate or external clock). Software-paced mode (`ScanRate = 0`) is not ported. | +| Structure | Three layers: link, device, source. The bottom two have no GTK or `DataSource` types. | + +## Design + +### 1. Files (new, `src/source/e1608/`, plus the mock) + +- `e1608_link.{hpp,cpp}`: UDP discovery (broadcast, or a unicast sweep of a given subnet + matched by MAC and the E-1608 product id) and connection-code handshake; TCP command + framing with a timeout; the scan socket on `port + 1`. Plain POSIX sockets. +- `e1608_device.{hpp,cpp}`: typed commands (AI, AO, DIO read/write/direction, counter + read/reset, scan queue, scan start/stop, status), the factory calibration read from the board's + calibration memory, and `decode()`, which turns raw interleaved `uint16` scans into calibrated + volts (`double`). +- `e1608_source.{hpp,cpp}`: the `DataSource`: the `poll()` state machine, `Frame` building, the + DI/counter and generator timers, the atomic readouts for the panels. +- `e1608_kind.cpp`: the `SourceKind`: the connect form and the two panels. +- `tools/mock_e1608.py`: the protocol mock. +- `register_builtin_sources()` registers `e1608` after `udps`. + +### 2. Data path and threading + +Everything runs inside `poll()` on the producer thread. The GTK thread reaches the board only +through `post(Command)`. + +`poll(timeout)`: + +1. Drains the posted commands (DAC writes, DIO toggles, counter reset, generator edits). +2. Runs the connection state machine: optional MAC lookup, handshake, calibration read, DIO + direction and initial outputs, scan queue and scan start take Disconnected to Scanning. A + link error fires `on_event(Disconnected)` and retries every 2 s. A connect attempt can block + `poll()` for up to the command timeout; that delays only the command queue. +3. Waits on the scan socket for at most the time to the next timer, reads what arrived, keeps a + partial scan for the next call, decodes the complete scans with the calibration and + delivers a `Frame`. +4. Runs the due timers: the DI/counter poll (`DiPollRate`) is a command round trip; the + generator tick (at most 10 Hz) is a DAC write. + +The frame: + +- Signals: the enabled AI channels (unit `V`, `range_min`/`range_max` from the channel's range), + the DI lines the user chose (0/1), and the counter if chosen. +- All signals are scalar; `num_samples` is the number of scans decoded in that read. +- DI and counter values are held across the block (a step trace). +- `sampling_rate` is the scan rate on every signal. `counter` is a running frame count. +- The aggregate rate (enabled channels times scan rate) must stay at or below 250 kS/s. The + form refuses a configuration above it. + +Overrun: if the board reports a scan overrun the source fires `on_event(Error)` and restarts +the scan when `AutoRestart` is set; the next frame carries `lost = 1`. This is approximate, +because the board does not report how many scans it dropped. + +Panel readouts: the source keeps the live DIO inputs, the counter, the DAC levels and the +generator state in atomics. The panels read them from a GTK timer, so no widget touches the +source's internals. + +### 3. Connect form and panels + +Connect form: grouped `AdwExpanderRow`s in the chooser's group. `SourceConfig` stays flat; a +per-channel setting is a key such as `ai0=BIP10V` (absent means off). + +- Connection: address, MAC, discovery subnet, port, connection code, timeout. `valid()` needs + an address, or a MAC plus a subnet. +- Acquisition: scan rate, external clock, trigger mode, auto-restart, calibrate (default on), + DI/counter poll rate. +- Analog inputs: global SE or DIFF mode and 8 channel rows (enable, range). In DIFF mode rows + 4 to 7 are insensitive, not hidden. `valid()` also enforces the 250 kS/s aggregate. +- Digital I/O: direction per bit (I or O), a "plot" switch per input bit, a "plot counter" + switch, the initial DO value and the initial DAC levels. + +`identity()` is the address, or the MAC when there is no address. A session file is named +`e1608-`, port 1, as sub-project 1 defines for non-UDPS kinds. `has_datagrams()` is +false, so the capture button is disabled. + +Two side-stack panels, both insensitive while disconnected (disabled, not hidden): + +- Analog out: per DAC, a mode (Level, Sine, Square, Triangle, Ramp), a level or amplitude plus + offset, a frequency of 0.1 to 10 Hz, and an on/off switch. It shows the last voltage written + and clamps to ±10 V. The generator stops on disconnect and the DACs return to their initial + levels on reconnect. +- Digital I/O: eight bit rows; an input bit shows a live LED, an output bit has a toggle that + posts a write. The counter shows its value and a Reset button. Directions come from the form + and are not changed at runtime. + +Tab icons are chosen in the plan under the project's bundled-icon rules. + +### 4. Verification + +Mock (`tools/mock_e1608.py`): UDP discovery with a MAC and the connection-code handshake; TCP +commands for AI, AO, DIO, the counter, scan queue, scan start/stop, calibration memory and +status; a scan stream on port+1 at the requested rate with a sine per channel; switches to drop +the link after N seconds and to report an overrun. Its header lists every command whose layout +is unverified (single reference, or the references disagree). + +Probe `UDPSCOPE_PROBE_E1608=`, run against the mock with `--source e1608`, extends the +probe/dump in `src/ui.cpp`. It checks: + +- Frames arrive with the expected channel count and sample rate. +- The panels are present and insensitive while disconnected. +- A DAC write, a DIO toggle and a counter reset each reach the mock. +- A forced link drop leads to a reconnect and a resumed stream. +- The calibration is applied (the mock serves non-trivial coefficients). + +A decode check needs no mock: a fixed raw buffer decoded against hand-computed volts. + +Baselines are unchanged: the UDPS self-check reads as on `main`, exactly three build warnings, +no `Gtk-CRITICAL`. + +Errors: a rejected handshake (bad connection code), no device found, timeouts and scan-socket +loss surface through `on_event(Error)` with a readable message and follow the reconnect cycle. +A rejected connection code stops the retries: the source stays in Error with that message until the user reconnects. + +Docs: update `architecture.md`, `build-and-run.md`, `verification.md`, `probe-readings.md` and +`README.md`. + +## Out of scope + +- Software-paced acquisition (`ScanRate = 0`). +- A generator faster than 10 Hz, and a dedicated I/O thread. +- Changing DIO directions at runtime. +- Per-channel SE/DIFF mixing (one global mode). +- Verification against a real board.