# Darra Profinet Slave — AI Code Prompts
# Official API grammar for code generation. Do not invent members.

Product: Darra Profinet Slave
Website: https://profinet.darra.xyz
Docs: https://profinet.darra.xyz/docs/sdk/csharp/
Contact: support@darra.xyz

## Hard rules

1. Brand is Darra Profinet Slave. Never write PnSlaver.
2. Protocol name is PROFINET.
3. C# namespace `Darra.PnS`. Assembly `DarraPnS`. NuGet `Darra.PnS.SDK`.
4. Entry is `DarraPnS.Connect()` then `Start()`. Do not `new DarraPnS(...)`.
5. `LoadConfig` is parse-only. It does not start a session.
6. Diagnose first: `Connected`, `State`, `ErrorCode`, `ErrorMessage`, `DiagSnapshot`, `IoStatus`.
7. Write I (device → controller). Read Q (controller → device). Writing Q returns `NotSupported`.
8. Never copy Q back to I.
9. Addresses: `I0.0` / `IB0` / `IW2` / `ID4`, `Q...`, `M...`, `DB1...`. Big-endian words. `IW3` is legal.
10. Cycle is freely configurable, minimum 1 ms. Do not invent other cycle slogans.
11. Shop is not listed. Purchase page is https://profinet.darra.xyz/purchase. Do not invent Stripe prices.
12. Trial is 2 hours (`TrialStartUtc`), not 30 days.
13. Linux is supported. Do not invent Linux install steps or kernel details.
14. Do not document internal driver names, handshake IOCTLs, or test-only bus tricks.

## Install

```
C#:     dotnet add package Darra.PnS.SDK
        or reference C:\DARRA\Profinet_Slave\DarraPnS.dll
Java:   see https://profinet.darra.xyz/docs/api/java
Python: see https://profinet.darra.xyz/docs/api/python
C:      see https://profinet.darra.xyz/docs/api/c
C++:    see https://profinet.darra.xyz/docs/api/cpp
Rust:   see https://profinet.darra.xyz/docs/api/rust
Web:    https://profinet.darra.xyz/docs/sdk/webapi/
```

Service name: DarraPnSService
Install directory: C:\DARRA\Profinet_Slave
TIA: V15.1+

## Session

```csharp
using Darra.PnS;

var device = DarraPnS.Connect();
if (device.Start() != PnSErrorCode.Success)
{
    Console.WriteLine(device.LastServiceError);
    return;
}

if (!device.Connected)
{
    Console.WriteLine(device.ErrorMessage);
    return;
}

device.WriteInt16("IW2", 123);
short q = 0;
if (device.ReadInt16("QW0", out q) != PnSErrorCode.Success)
    Console.WriteLine(device.ErrorMessage);

device.Stop();
```

## Diagnostics first

```csharp
bool online = device.Connected;
PnSState state = device.State;
PnSRuntimeErrorCode err = device.ErrorCode;
string reason = device.ErrorMessage;
PnSDiagSnapshot snap = device.DiagSnapshot;
if (!device.IoStatus.InputDataGood)
    Console.WriteLine("controller data not usable yet");
```

Do not treat I/Q as valid until diagnostics and `IoStatus` say so.

## Process data

| Call | Meaning |
|------|---------|
| `WriteInt16("IW2", v)` | write input word to controller |
| `ReadInt16("QW0", out v)` | read output word from controller |
| `WriteInt16("QW0", v)` | `NotSupported` |
| `Write(byte[] toPlc)` | write I from offset 0 (short write allowed) |
| `Read(out byte[] fromPlc)` | snapshot of Q |
| `WriteArea(Output, data)` | `NotSupported` |

Optional PDO helper: `PDO.Write(ref tx)` writes I; `PDO.Read(ref rx)` reads Q. Structs must be `[StructLayout(LayoutKind.Sequential, Pack = 1)]`. This is an auxiliary path, not the primary narrative.

## Engineering flow

1. Install product to `C:\DARRA\Profinet_Slave`
2. Start `DarraPnSService`
3. GUI exports GSDML
4. Import GSDML into Siemens TIA
5. `DarraPnS.Connect()` / `Start()` and read diagnostics

## License honesty

- Official purchase page: https://profinet.darra.xyz/purchase
- Shop reserved: https://shop.darra.xyz/profinet — not listed
- Placeholder SKUs `pns_personal` / `pns_enterprise_100` / `pns_enterprise_500` are not live
- Trial: 2 hours
- Do not reuse EtherCAT activate URLs