docs: extend Newport evaluation with order, wiring, encoders, homing

Adds mounting variants for setup B, initialization/homing of the incremental
stages, Newport cart with lead times, XPS-DRV11 DB25 pinout, XPS encoder
interfaces and notes for a custom Steinmeyer/OWIS stepper cable.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M8zoDvpeC2s153trRfq32w

vendor_docs/newport_xps/newport_sastt_evaluation.md

@@ -45,6 +45,79 @@ exact edges from the hardware latch. **Kilohertz dwell: yes**, limit ~10 kHz lat
 - Abbe error and residual vibration: interferometer/capacitive sensor at the sample, captured by the PandA on
   the same gates (value, mean, min/max per gate). XPS gathering stays as diagnostic stream.
 
+## Mounting variants considered (setup B)
+
+- **ILS on its side (90°), PMT160 symmetric about the guide, motor end down as counterweight:** centre of mass
+  near the guide, so almost no tilting torque during acceleration; the sample offset couples to ILS *yaw*
+  (±25 typ / ±75 guar. µrad, i.e. ±4 / ±11 µm at 150 mm) instead of pitch. Not covered by Newport specs (only
+  Cz = 250 N normal load), would need confirmation for side load and ~3 Nm roll moment.
+- **Decision for now: ILS horizontal**, PMT160 on a stiff right-angle bracket centred on the carriage, working
+  range kept low. Abbe error is accepted for positioning and removed from the data by external metrology.
+
+## Initialization and homing
+
+- Both Newport stages have **incremental** encoders (ILS: 20 µm steel scale 1 Vpp, home mark on the reference
+  track at mid travel; VP-5ZA: 20 µm scale, optical origin at mid travel).
+- ILS: ironless linear motor without Hall sensors, so `GroupInitialize` runs a short **commutation routine**
+  (small motion) before `GroupHomeSearch` (≤ 150 mm travel to the centre mark). Clear the motion envelope first.
+- `GroupMotionDisable` keeps the encoder running: switching tuning profiles does not lose the reference. Reboot,
+  power loss or `GroupKill` require init + homing again. BEC can run the sequence over TCP (to be decided:
+  manual step or guarded BEC procedure).
+
+## Order (Newport guest cart, list prices, 2026-11-09)
+
+| Item | Price | Delivery |
+|---|---|---|
+| XPS-RLD4 controller, 4 axes | €7,766 | 28.12.2026 (7 weeks) |
+| M-ILS300LM-S linear motor stage, 300 mm | €8,337 | 28.12.2026 (7 weeks) |
+| M-VP-5ZA vertical stage, 4.8 mm | €9,312 | 18.12.2026 (6 weeks) |
+| XPS-DRV02 driver (brushless, for ILS) | €1,266 | in stock (13.11.2026) |
+| XPS-DRV11 universal driver (stepper/DC/linear) | €825 | in stock (13.11.2026) |
+| XPS-DK26 cable kit (ILS-LM-S on DRV02) | €428 | in stock (13.11.2026) |
+| XPS-DK22 cable kit (IMS-LM-S/XMS/XML on DRV11) | €452 | in stock (13.11.2026) |
+| **Total** (items €28,386 + surcharge €851.58) | **€29,237.58** | complete end of Dec 2026 |
+
+- **VP-5ZA needs no cable kit:** it has a fixed 1.5 m cable with Sub-D25, which plugs directly into the DB25 of
+  the XPS-DRV11. The DK kits are only for direct-drive stages.
+- **XPS-DK22 is probably not needed** (selection table in the cable kits manual: IMS-LM-S, XMS-S, XML-S on DRV11).
+  Remove unless such a stage is planned.
+
+## XPS-DRV11: connector and wiring (Start-Up Manual, Appendix E)
+
+Female DB25 on the card; mating connector male Sub-D25 with UNC 4-40 lockers. Stepper: bipolar, microstep,
+max. 3 A rms per phase, 47 V. DC: 6 A peak, 47 V.
+
+| Pin | Stepper | DC motor | Brushless | Pin | All motors |
+|---|---|---|---|---|---|
+| 1, 2 | +Phase 1 | – | Phase U | 13 | Origin (home) |
+| 3, 4 | −Phase 1 | – | – | 14, 16, 22 | GND |
+| 5, 6 | +Phase 2 | Motor+ | Phase V | 15 / 25 | Index / /Index (RS-422) |
+| 7, 8 | −Phase 2 | Motor− | Phase W | 17 / 18 | +Limit / −Limit |
+| 9 | – | – | Thermistor | 19 / 23 | Encoder A / /A (RS-422) |
+| 10-12 | – | – | Hall U/V/W | 20 / 24 | Encoder B / /B (RS-422) |
+|  |  |  |  | 21 | +5 V (max. 0.25 A) |
+
+Motor phases are on two pins each, wire both. Limits, origin and other servitudes: **TTL 0-5 V, normally closed
+to GND, active when open**, 2.2 kΩ pull-up to +5 V, read at the servo rate. 24 V or PNP sensors need a level
+adapter.
+
+## Encoder interfaces of the XPS
+
+| Type (`EncoderType` in stages.ini) | Connector | Notes |
+|---|---|---|
+| `AquadB`: RS-422 square wave A/B/I | DB25 of the driver card | differential, 120 Ω termination, 5 V supply from the card |
+| `AnalogInterpolated`: sine/cosine 1 Vpp | HD26 "Analog Encoder" per axis on the controller (male SUB-D26HD mating) | ×65536 interpolation, max. 2.4 MHz input; used by the ILS; PCO with ×256 (basic) or ×65536 (extended) |
+| `NoEncoder` | – | open-loop stepper (PMT160-SM, OWIS HiSM) |
+| absolute (MA/SLO clock/data pins on HD26) | HD26 | **not documented** in the Configuration Manual; only on newer control boards/firmware; protocol (SSI/BiSS?) to be asked at Newport |
+
+## Custom cable for Steinmeyer PMT160 (and OWIS HVM stepper stages)
+
+- Sub-D25 male to the XPS-DRV11: phases on pins 1-8, limits 17/18, origin 13, GND, +5 V if the sensors need it.
+- Check: motor rated current ≤ 3 A rms; limit/home sensor type and voltage (must end up as 5 V TTL, NC to GND).
+- PMT160-SM has no encoder (`NoEncoder`). The PMT160-DC variant with encoder should provide RS-422 square wave
+  (DB25) or 1 Vpp sine (HD26).
+- Pin assignment of the Steinmeyer connector: from the Steinmeyer data sheet, mapping table still to be made.
+
 ## Vendor documents
 
 Controller (for coding), in this folder (`vendor_docs/newport_xps/`) - XPS Unified Programmer's Manual, XPS-D Features