prins-fixture

Prins Fixture

Overview

The Prins switch fixture is a legacy hardware test fixture communicating over TCP (ASCII protocol). It is not part of the test framework — it is a standalone legacy system. Commands are plain ASCII strings; responses start with SD or STR.

Fixture interaction is done via prins-fixture-mcp — a Python MCP server that exposes every command as a tool callable from Claude Code.

MCP Server (prins-fixture-mcp)

Location: SwitchTests/PrinsFixtureMCP/server.py

Install & run:

pip install mcp
python PrinsFixtureMCP/server.py

Register in .claude/settings.json:

{
  "mcpServers": {
    "prins-fixture-mcp": {
      "command": "python",
      "args": ["C:/Users/JuliandeBruin/Documents/AmpelTesting/TestDevelopment/PrinsTests/SwitchTests/PrinsFixtureMCP/server.py"]
    }
  }
}

Always call connect_fixture(ip, port) first; all other tools fail without an active connection.

TCP Protocol

Format	Example	Notes
PutXxx...	PutFixtSt:001	Write command, response discarded
GetXxx...	GetFixtSt	Read command, returns SD... response
DiaXxx...	DiaTstBuz00	Diagnostic command
Response prefix SD	SDFixtSt:1	Normal fixture response
Response prefix STR	STRIndLoc:Updating	Status update response

Available MCP Tools

Connection

• connect_fixture(ip, port) — open TCP connection (3 s timeout)
• disconnect_fixture() — close connection

Switch Count

• set_number_of_switches(n) — write PutSwiCnt00XX
• get_number_of_switches() — send GetSwiCnt

LEDs (position indicators)

• set_all_leds(color) — all 64 slots, color: Red/Green/Both/Off
• set_led(index, color) — single slot
• set_multiple_leds(indices, active_color, inactive_color) — bulk set

Colors map: Red=0 Green=1 Both=2 Off=3

Fixture Identity & Status

• get_fixture_id() — GetFixtID
• get_fixture_status() — GetFixtSt → SDFixtSt:N
• set_fixture_status(status) — status: Empty/Assembly/Testing/Packaging/Service

Status command map:

Empty      → PutFixtSt:000
Assembly   → PutFixtSt:001
Testing    → PutFixtSt:002
Packaging  → PutFixtSt:004
Service    → PutFixtSt:008

Switch Diagnostics

• check_switch_present(index) — GetPresenXX, checks for "1" in response
• check_switch_version(index) — GetVerNumXX, decodes HW rev (bits 7:5) and App rev (bits 4:0); minimum OK = HW=1, App≥10

EEPROM (PN / SN)

• program_switch_eeprom(index, pn, sn) — PutSwEromXX[32 hex]
• get_switch_eeprom(index) — GetSwEromXX, decodes to PN and SN

PN format: XXX/XXXXXX/L (12 chars, e.g. 600/025250/A) SN format: A/WW/YY/BPPP (12 chars, e.g. A/26/24/1001)

EEPROM layout (16 bytes, 32 hex chars):

[0]  Version (0x02)
[1-3] Reserved (0x000000)
[4]  Batch
[5]  Year
[6]  Week
[7]  Reserved
[8]  Batch number part 1
[9]  Batch number part 2
[10-13] PN numeric fields
[14] PN last digit × 10
[15] PN hw-rev letter (ASCII)

Pass / Fail

• store_pass_fail(index, passed) — PutPasFaiXX[0|1]
• get_pass_fail(index) — GetPasFaiXX

Button Test

• initialise_button_test() — PutButIni
• get_button_result() — GetButRes, returns indices where button was NOT pressed (char '0')

Buzzer Test

• get_buzzer_amplitude(index) — DiaTstBuzXX
• test_buzzer(index) — GetTstBuzXX, returns amplitude,volume

LED Test Commands

• turn_on_test_led(index) — PutTstLED00XX
• turn_on_test_rgb_led(index, color) — PutTstRgb00XY
• turn_on_multiple_rgb_leds(color, num_leds) — DiaTstRgb00XYYY
• turn_on_single_led_on_switch(switch, led, color) — PutSglLedXXYZ
• turn_on_all_white_leds() — PutAllLED
• get_daylight_sensor_values() — GetTstIlu

Escape Hatch

• send_raw_command(message, expect_response) — send any raw ASCII string

Common Tasks

• Set fixture to assembly mode: call set_fixture_status("Assembly")
• Check all switches present: call check_switch_present for each index 0–(n-1)
• Program a switch: call program_switch_eeprom(index, pn, sn) — PN must be 12 chars, SN must be 12 chars
• Run button test: initialise_button_test() → ask user to press all switches → get_button_result()
• Debug LED positions: use set_multiple_leds with active_color="Red" and inactive_color="Off" to highlight specific slots