Siglent Scope

---
name: siglent-scope
description: Remote-control a Siglent SDS1000X-E series oscilloscope (SDS1104X-E, SDS1204X-E, etc.) over the network — SCPI command essentials, screenshots, deep-memory waveform transfer, and the firmware quirks that hang naive clients. Use when the user wants to talk to, automate, screenshot, or pull waveform data from a Siglent SDS1000X-E-series scope.
---

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SPDX-FileCopyrightText: 2026 contributors
SPDX-License-Identifier: Apache-2.0
-->

# siglent-scope

Remote control and data transfer for Siglent SDS1000X-E series scopes
(verified on an SDS1104X-E, firmware 6.1.37R17). No VISA stack needed —
everything below works over a plain TCP socket.

## Finding and reaching the scope

Resolve the address in this order:

1. An explicit address from the user, a local companion skill, or
   project docs.
2. `$SCOPE_HOST` env var.
3. The bare hostname **`scope`** — the default convention; it resolves
   via the local DNS search domain when the scope has a DNS entry.
   Verify with the sanity check below before assuming.
4. Otherwise ask the user. The scope shows its IP under
   Utility → I/O → LAN.

Endpoints (ports are fixed):

- **:5025** — raw SCPI socket (preferred; one client at a time)
- :5024 — telnet SCPI
- VXI-11 (works with pyvisa `TCPIP::<host>::INSTR`)
- :80 — embedded web UI / virtual front panel (4-channel models)

Sanity check:

```bash
printf '*IDN?\n' | nc -w 3 <scope-host> 5025
```

## SCPI essentials (LeCroy-derived dialect)

- Send `CHDR OFF` first — strips echoed headers from query replies.
  Persists on the instrument across connections.
- Common queries: `*IDN?`, `TDIV?`, `SARA?` (sample rate), `C1:VDIV?`,
  `C1:OFST?`, `SANU? C1` (acquired points), `TRMD?`, `MSIZ?`. Settings are
  the same commands with a value (`TDIV 1MS`, `C1:TRLV 1.5V`, `MSIZ 14M`).
- **Screenshot**: `SCDP` returns a raw 800×480 BMP — no length prefix;
  parse the file size from BMP header bytes 2–5 (little-endian), then one
  trailing `\n`.
- **Waveform**: `WFSU SP,0,NP,0,FP,0` (all points) then `C1:WF? DAT2`.
  The reply embeds `#9<nine ASCII digits = byte count><int8 payload>`
  followed by exactly two `\n` bytes.
  Volts = code × (VDIV/25) − OFST; time axis from `SARA?`.

## Firmware quirks (observed on 6.1.37R17 — these WILL hang naive clients)

- **`SAST?` never replies while trigger mode is STOP** — the connection
  hangs forever, no error. Poll `INR?` bit 0 instead (latched
  acquisition-done flag, clears on read; read once before arming to
  discard stale state).
- **`ARM` force-starts a sweep immediately** — it does NOT merely arm.
  `TRMD SINGLE` alone is how you arm and wait for a real trigger.
- **`FRTR` (force trigger) is a no-op while armed in SINGLE mode.** To
  force a stuck single acquisition, send `ARM`.
- **Any `MSIZ` write clamps `TDIV` to 1 ns/div** — even rewriting the
  value MSIZ already has — and the clamp can land asynchronously AFTER a
  subsequent `TDIV` write. Round-trip any query after `MSIZ`, then set
  `TDIV` and verify the read-back in a retry loop until it sticks.

## Hardware facts (X-E series)

- Channels share ADCs in pairs (CH1/CH2 and CH3/CH4 on 4-ch models).
  Full sample rate (1 GSa/s) and full memory (14 Mpts) per channel only
  when ≤1 channel of each pair is active — for two-channel work use
  **C1 + C3**.
- 14 Mpts @ 1 GSa/s = 14 ms record; a 14 Mpts × 2-channel pull over the
  :5025 socket takes ~4.5 s (~6.4 MB/s), delivered as a single `WF?`
  block — no chunking required.
- 100/200 MHz analog bandwidth: fine for USB low/full-speed signal
  integrity work; not usable for USB high speed (480 Mb/s).

## Reference

[SDS1000X-E Programming Guide](https://www.batterfly.com/PDF/Siglent/SDS1000X-E/SDS1000X-E_programmingguide_EN.pdf)
— full command set. Where this skill's quirks list conflicts with the
guide, trust the quirks list; it was verified on the wire.