# E03 Pulse Width

### Definition

Sets the pulse width of the flow meter when **E02 OCT Info** is set to “**Pulse v2**”. Default: 0.5 ms.\\

<details>

<summary><strong>Pulse Output – Pulse V2 Function</strong> <em>(Click to Expand)</em></summary>

### 1. Technical Principle: Pulse V2 “Batch Reporting” Mechanism

Pulse V2 differs from traditional continuous variable-frequency pulse output. It uses a **periodic pulse burst** mechanism.\
At the end of each update cycle, the system converts the accumulated flow into a burst of pulses and transmits them in a short period of time.

**A19 Defines the “Reporting Cycle”:**

* **A19 = 1.0 s (Default):**\
  Flow is accumulated every 1 second, and the corresponding pulse burst is transmitted during the following 1 second.
* **A19 = 0.5 s (High-speed):**\
  Flow is accumulated every 0.5 seconds, and the corresponding pulse burst is transmitted during the following 0.5 seconds.

***

### 2. Parameter Configuration Table

| Parameter Code | Name          | Function Description   | Setting Recommendation                                                                                                          |
| -------------- | ------------- | ---------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| A19            | Fast Update   | Flow Calculation Cycle | <p>1.0 s: Suitable for general PLC applications.<br>0.5 s: Suitable for high-precision or high-speed counting applications.</p> |
| E02            | OCT Info      | Output Mode Selection  | Pulse V2 must be selected.                                                                                                      |
| E14            | Pulse V2 Unit | Flow per Pulse         | Determines the resolution (e.g., 0.1 represents 0.1 L/pulse).                                                                   |
| E03            | Pulse Width   | Signal Duration        | Determines whether the PLC can correctly capture the signal.                                                                    |

### 3. Core Steps: Settings Based on PLC Type

**Option A: Connected to General PLC Input (Common DI)**

* **Applicable for:** PLCs without high-speed counting modules or with slow scan cycles (>10 ms).
* **A19 (Update Frequency):** Recommended **1.0 s** (updates once per second).
* **E14 (Resolution):** Recommended **large** (e.g., 0.1 or 1.0).
* **E03 (Pulse Width):** Recommended **50 ms**.
* **Limitation:** When the flow rate is high, the total number of pulses should not be too large, otherwise all pulses may not be transmitted within 1 second.

**Option B: Connected to PLC High-Speed Counting Module (HSC)**

* **Applicable for:** Precise quantitative control and high-resolution monitoring.
* **A19 (Update Frequency):** Can be set to **0.5 s** (updates every 0.5 seconds).
* **E14 (Resolution):** Can be set **small** (e.g., 0.01 or 0.001).
* **E03 (Pulse Width):** Recommended **0.5 ms** (default) or **1 ms**.
* **Limitation:** Although HSC can read high-frequency signals, it must still ensure that all pulses can be transmitted within 0.5 seconds.

***

### 4. Frequency Safety Check (Error Prevention Calculation)

To prevent **signal overlap (“traffic jam”)** that may cause the PLC to miss pulses, the following calculation should be performed: verify whether the **pulse burst** generated at maximum flow can be fully transmitted within the **A19 reporting cycle**.

#### 1. Calculate the Number of Pulses per Cycle (N)

First, calculate the maximum number of pulses the flowmeter can generate within one update cycle:

$$N = \frac{(\mathrm{Maximum\ LPM} / 60) \times \mathrm{A19\ Cycle\ (s)}}{E14}$$

#### 2. Determine Safety Standard

To ensure sufficient spacing between pulses (recommended **50% duty cycle**), the following condition must be met:

$$N×(E03×2)< A19 cycle (s)$$

> 💡 **Why multiply by 2?**
>
> A complete pulse cycle consists of **high-level time (E03)** and **low-level interval time**. To ensure stable detection by the receiving device (PLC), it is generally recommended that the interval time be at least equal to the pulse width.

***

#### Example Scenario Calculation

Assume the following site conditions and settings:

* **Maximum Flow:** 60 LPM
* **A19 (Cycle Time):** 1.0 s
* **E14 (Pulse Unit):** 0.1 L/pulse
* **E03 (Pulse Width):** 50 ms (0.05 s)

**Step 1: Calculate Number of Pulses**

$$N = \frac{(60 \div 60) \times 1.0}{0.1} = 10 \text{ (pulse)}$$

**Step 2: Check Safety Standard**

$$10 \times (0.05 \times 2) = 1.0\text{s}$$

**Result Evaluation:**\
The calculated transmission time is **1.0 s**, exactly equal to the A19 cycle time. This indicates that the signal is at the **“limit”** state, with almost no extra spacing between pulses. If the actual flow exceeds 60 LPM, pulses may overlap, causing the PLC to miss counts.

**Optimization Suggestions:**

* **Option A:** Increase **E14** (e.g., set to 0.2) to reduce the number of pulses by half.
* **Option B:** Decrease **E03** (e.g., set to 20 ms) to shorten the duration of each pulse.

***

### 5. Troubleshooting

**Q1: The panel shows flow, but the PLC does not receive any values**

* **Cause A:** **E03 (Pulse Width)** is set too short and is filtered out by the PLC.\
  **Solution:** Increase **E03** to 50 ms.
* **Cause B:** **E02** is not set to **Pulse V2**.

**Q2: PLC misses counts or stops increasing at high flow rates**

* **Cause:** Signal overlap. Pulses are too wide and dense, causing the high-level signal to “stick” and form a straight line.\
  **Solution A:** Increase **E14** (e.g., 0.01 → 0.1) to reduce the total number of pulses.\
  **Solution B:** Decrease **E03** (e.g., 10 ms → 1 ms) to increase spacing between pulses.

**Q3: PLC cumulative value does not match the flowmeter panel**

* **Cause:** Pulse frequency approaches the PLC’s sampling limit, causing occasional missed counts.
* **Solution:** Increase **E14** to use a larger pulse unit (e.g., change from 1 mL/pulse to 10 mL/pulse).

</details>

### Notes

To enable the pulse function, set **E02 OCT Info** to **“Pulse v2”**, configure the pulse width in **E03 Pulse Width**, set the forward flow unit in **B01**, and define the pulse output reference unit in **E14 Pulse v2 Unit**.

### Operation Procedure

<details>

<summary><strong>Button Functions</strong> <em>(Click to Expand)</em></summary>

When the main screen is displayed in **green backlight**, the four buttons function as follows:

* <img src="https://4028902321-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSBz5Tlpy8GCIkK4ygkgZ%2Fuploads%2FRnX1fMK1ja5FUx043ZYc%2Fimage?alt=media&#x26;token=f31dd577-ba27-4369-af8b-25ce9afcd1f9" alt="" data-size="line"> **Blue Button (leftmost):** Return, exit, or save settings.
* Gray Direction Buttons:
  * <img src="https://4028902321-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSBz5Tlpy8GCIkK4ygkgZ%2Fuploads%2FR48KXgI2flteQ78PYH8a%2Fimage?alt=media&#x26;token=b5b4ab82-6f88-44c6-8b85-181c7bde6fe9" alt="" data-size="line"> **Left Gray:** Previous Page, decrease value, or select item
  * <img src="https://4028902321-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSBz5Tlpy8GCIkK4ygkgZ%2Fuploads%2FVWLxHCjTZgj8Y3CXUn6X%2Fimage?alt=media&#x26;token=35556f59-f963-4b03-8db1-34f2953ddb58" alt="" data-size="line"> **Right Gray:** Next Page, increase value, or select item
* <img src="https://4028902321-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSBz5Tlpy8GCIkK4ygkgZ%2Fuploads%2F0lsHAW4cWIphk6mKtEoK%2Fbutton-orange.png?alt=media&#x26;token=9168c231-821c-4895-9194-0cf61b2fd06a" alt="" data-size="line"> **Orange Button (rightmost):** Rightmost button: Enter settings, edit, or confirm selection

{% hint style="danger" %}
**Do not hold buttons for extended periods to avoid damage.**
{% endhint %}

{% hint style="info" %}
Button functions may change depending on the operation context to improve usability or prevent accidental presses.
{% endhint %}

</details>

```
E03 Pulse Width Setting Steps
• From the main screen (green backlight), 
  press Orange Button (Setup) to enter settings (orange backlight).
• Use Gray Arrow Buttons to select E. Commute , press Orange Button (Enter).
• Use Gray Arrow Buttons to select E03 Pulse Width, press Orange Button (Enter).
• Use Gray Arrow Buttons to choose the options. 
• Press Orange Button (Set) to confirm.
• Press Blue Button (ESC) to return to the main screen (green backlight).
```

<figure><img src="https://4028902321-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSBz5Tlpy8GCIkK4ygkgZ%2Fuploads%2FvQ5qy4DVunfgLP1etTdc%2Ffu-es-E03-en.png?alt=media&#x26;token=b7a933c8-2e99-4c91-901b-7168e250cc46" alt="" width="563"><figcaption></figcaption></figure>

### E03 Options, RS485 Values, Read/Write Commands, and Formats

| Option           | Description | RS-485 Value |
| ---------------- | ----------- | ------------ |
| 0.5 ms (Default) | -           | 0            |
| 1 ms             | -           | 1            |
| 10 ms            | -           | 2            |
| 50 ms            | -           | 3            |
| 100 ms           | -           | 4            |

> Refer to the [Read/Write Memory List](https://docs.lorric.com/qr/fu-es-echosense-instruction-manual/communication/modbus-rtu-protocol/read-write-memory-ram) for the Modbus command format. This parameter uses the Int16 data format.