> For the complete documentation index, see [llms.txt](https://docs.lorric.com/qr/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lorric.com/qr/fu-lt-english-v1/communication/npn-output.md).

# NPN Output

## **Specifications**

### **NPN Output**

| Power Supply                | 24V 200mA                            |
| --------------------------- | ------------------------------------ |
| Reverse Polarity Protection | Yes                                  |
| NPN Wiring                  | Supported (PNP wiring not supported) |

## Wiring

### NPN Output Wiring Diagram

* **Brown:** 24 VDC (+), **Blue:** 0 VDC (–), **Orange:** NPN Output (+)

This function operates only when the brown and blue lines are powered by a DC supply.

<div align="left"><figure><img src="/files/2uj82ey3Hxy2NKQAD6hf" alt="" width="563"><figcaption></figcaption></figure></div>

### NPN Parameter Configuration

Follow the steps below to configure NPN output parameters:

{% stepper %}
{% step %}

### Set Basic Parameters

* Refer to the [**Parameter Settings**](/qr/fu-lt-english-v1/installation-and-setup/parameter-settings.md) page and complete the following steps: **Language Setting, Pipe Settings:A02:** Pipe Standard, **A04:** Pipe Outer Diameter, **A06:** Pipe Wall Thickness, **A08:** Pipe Material
* Execute **Z03 (Automatic Initialization)**.
  {% endstep %}

{% step %}

### **Wiring Setup**

Connect the NPN output wiring according to the instructions on this page.
{% endstep %}

{% step %}

### **E01 – NC/NO (Normally Closed or Normally Open)**

Set parameter **E01 NC/NO** to select the default state:

* **NC (Normally Closed):** Conducting when idle
* **NO (Normally Open):** Open when idle
  {% endstep %}

{% step %}

### **E02 – OCT Definition (Output Signal Type)**

Set parameter **E02 OCT Info** to specify the output signal.

* If “Pulse V2” is selected:
  * Use **E03 Pulse Width** to set the duration of each pulse.
  * Use **E14 Pulse V2 Unit** to define the capacity represented by each pulse.
* If “Total Alarm” is selected:

  * Use **D09 Total Alarm** to enable the alarm.
  * Use **D10 Total Trig.** to set the trigger condition:
    * **“Greater than Target”** for forward flow
    * **“Less than Target”** for reverse flow
  * Use **D11 Total Target** to specify the cumulative target:
    * Positive value for forward flow
    * Negative value for reverse flow

  (See Note 1)
* If “Flow Alarm” is selected:

  * Use **D05 FlowLIM Alarm** to enable the flow range alarm.

  * Use **D06 UP LIM** (Upper Limit) and **D07 Low LIM** (Lower Limit) to define the normal flow range.

  > **Note:** If either **D06** or **D07** is adjusted, the other must also be set; otherwise, the display may not function correctly. If both are unset, default values are **D06 = 100**, **D07 = 0**.

  * Use **D08 Hysteresis** to define the hysteresis operation method. Values must be positive and expressed as a percentage; larger values reduce repeated alarm triggers.

  (See Note 2)
  {% endstep %}

{% step %}

### Return to the main screen. Complete.

{% endstep %}
{% endstepper %}

### Note 1

<details>

<summary><strong>D09、D10、D11 Total Alarm Examples</strong></summary>

```
Example 1: Forward Flow
Enable D09 Total Alarm.
Set D10 Total Trig. to “Greater than Target”.
Set D11 Total Target to a positive value, e.g., +100.
When the cumulative forward flow exceeds 100, 
the system triggers the total alarm.

Example 2: Reverse Flow
Enable D09 Total Alarm.
Set D10 Total Trig. to “Less than Target”.
Set D11 Total Target to a negative value, e.g., -500.
When the cumulative reverse flow drops below -500, 
the system triggers the total alarm.
```

</details>

### Note 2

<details>

<summary><strong>Flow Range Limit Alarm Example (Click to Expand)</strong></summary>

```
D06 Upper Limit: 30 LPM
D07 Lower Limit: 10 LPM
D08 Hysteresis: 3% (default)

Calculations:
Range: 30 − 10 = 20 LPM
Hysteresis: 20 × 3% = 0.6 LPM

Alarm Behavior:
When flow exceeds the upper limit (30 LPM), the alarm is triggered.
The alarm will clear only when the flow drops below 29.4 LPM (30 − 0.6).
When flow falls below the lower limit (10 LPM), the alarm is triggered.
The alarm will clear only when the flow rises above 10.6 LPM (10 + 0.6).
```

</details>


---

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