# Load and Unload Solder Paste Printer Durables

## Overview

This feature enables the load and unload of durable materials on Solder Paste Printer machines,
triggered by Fuji Nexim equipment events. The following durable types are supported:

- **Screen** — attached at position 1 (`Screen`)
- **Squeegee Holders** — attached at positions 4 and 5 (`HolderFront` and `HolderRear`)
- **Backup Block** — attached at position 6 (`BackupBlock`)

### Relevant Artifacts

| Name                                                                             | Type       | Is Mandatory | Data Type | Description                                                                                                            |
| :------------------------------------------------------------------------------- | :--------- | :----------: | :-------- | :--------------------------------------------------------------------------------------------------------------------- |
| IoTMetadataDefinition                                                            | SmartTable | Yes          |           | Metadata configuration used to enable or bypass the durable handling feature per resource.                             |
| [IoTFujiNeximHandleScreen](../../artifacts/dees.md#iotfujineximhandlescreen)     | DEE        | Yes          |           | Attaches or detaches a Screen durable at position `Screen` on a specified MES resource.                                |
| [IoTFujiNeximHandleSqueegee](../../artifacts/dees.md#iotfujineximhandlesqueegee) | DEE        | Yes          |           | Attaches or detaches Squeegee Holder durables at positions `HolderFront` and `HolderRear` on a specified MES resource. |
| [IoTFujiNeximHandleBackupBlock](../../artifacts/dees.md#iotfujineximhandlebackupblock)     | DEE        | Yes          |           | Attaches or detaches a Screen durable at position `Screen` on a specified MES resource.                                |

## How It Works

When a `LOADSCREEN`, `UNLOADSCREEN`, `LOADSQUEEGEE`, `UNLOADSQUEEGEE`, `LOADBACKUPBLOCK` or `UNLOADBACKUPBLOCK` event is received from
the Fuji Nexim equipment, the following steps are executed:

### Area Feature Checks

- Resolves the MES Sub-Resource Name using the pattern:
  `FUJI_LineNameMachineName_{EquipmentLineName}_{EquipmentMachineName}`.

### Resource Feature Checks

- Checks whether the `UseFujiToHandleScreen`, `UseFujiToHandleSqueegee` or `UseFujiToHandleBackupBlock` feature is enabled for
  the resolved MES Resource in the `IoTMetadataDefinition` Smart Table.

### MES Operations

If the feature is enabled, the Automation Controller calls the respective DEE.

**IoTFujiNeximHandleScreen:**

- Validates the screen durable material identified by `ScreenID`.
- Performs the operation based on the `Operation` input:

    **Load:**

    - If a durable with the name matching `ScreenName` is already attached at position `Screen`, no action is performed and `Success` is returned immediately.
    - Otherwise, any durable currently attached at position `Screen` is detached and the new screen durable is attached at that position.

    **Unload:**

    - Any durable currently attached at position `Screen` is detached.

- Sends a `LOADSCREEN_ACK` or `UNLOADSCREEN_ACK` message back to the equipment with:
    - A result (`0` = Ok, `1` = NOk) for the operation.

---

**IoTFujiNeximHandleSqueegee:**

- Validates the resource has at least 5 Durable Positions defined.
- Performs the operation based on the `Operation` input:

    **Load:**
    - Iterates through the `SqueegeeComponents` list (one entry per holder).
    - Maps `Location 0` → position `HolderFront` and `Location 1` → position `HolderRear`.
    - If a holder is already attached at the correct position, no action is performed for that entry.
    - Otherwise, any durable currently at that position is detached and the new holder is attached.
    - If the holder material does not exist in MES, that entry is marked as failed (`Result = 1`).

    **Unload:**
    - All durables currently attached at positions `HolderFront` and `HolderRear` are detached.

- Sends a `LOADSQUEEGEE_ACK` or `UNLOADSQUEEGEE_ACK` message back to the equipment with:
    - A list of components.
    - A result (`0` = Ok, `1` = NOk) for each component.

**IoTFujiNeximHandleBackupBlock:**

- Validates the screen durable material identified by `BackupBlockID`.
- Performs the operation based on the `Operation` input:

    **Load:**

    - If a durable with the name matching `BackupBlockName` is already attached at position `BackupBlock`, no action is performed and `Success` is returned immediately.
    - Otherwise, any durable currently attached at position `BackupBlock` is detached and the new backup block durable is attached at that position.

    **Unload:**

    - Any durable currently attached at position `BackupBlock` is detached.

- Sends a `LOADBACKUPBLOCK_ACK` or `UNLOADBACKUPBLOCK_ACK` message back to the equipment with:
    - A result (`0` = Ok, `1` = NOk) for the operation.

**Error Handling**
If any step fails during a DEE operation (e.g. material not found, insufficient durable positions,
missing mandatory input), the operation is considered failed and an error is returned to the equipment.

**Bypass Condition**
If `UseFujiToHandleScreen`, `UseFujiToHandleSqueegee` or `UseFujiToHandleBackupBlock` is set to `False` or is not defined in
`IoTMetadataDefinition`, the respective DEE call is bypassed entirely and no MES operation is performed.

### Assumptions

The `IoTMetadataDefinition` Smart Table must be configured with the following entries for each station:

| Resource                    | ResourceType | Area           | Name                    | Value |
| --------------------------- | ------------ | -------------- | ----------------------- | ----- |
|                             |              | Fuji Line Area | FUJI_LineNameMachineName_{EquipmentLineName}_{EquipmentMachineName} | MES ResourceName    |
| MES Fuji Station X Resource |              |                | UseFujiToHandleScreen   | True  |
| MES Fuji Station X Resource |              |                | UseFujiToHandleSqueegee | True  |
| MES Fuji Station X Resource |              |                | UseFujiToHandleBackupBlock | True  |