# A19 Fast Update ### Definition This function increases the flowmeter display update rate to once every **0.5 seconds**. The default setting is **disabled**.
Pulse Output – Pulse V2 Function (Click to Expand) ### 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 |

1.0 s: Suitable for general PLC applications.
0.5 s: Suitable for high-precision or high-speed counting applications.

| | 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).
### Notes N/A ### Operation Procedure
Button Functions (Click to Expand) The main unit has **four buttons**. The **bottom line (Line 3)** of the LCD displays the current function of each button. Under normal operation, the button functions are as follows: * **Blue Button -** Leftmost button: Return, exit, or save settings. Gray Arrow Buttons: * **Left Gray Button:** Previous Page, decrease value, or select item * **Right Gray Button:** Next Page, increase value, or select item * **Orange Button:** 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 %}
``` A19 Fast Update Setting Steps • From the main screen (green backlight), press Orange Button (Setup) to enter settings (orange backlight). • Use Gray Arrow Buttons to select A. Measure , press Orange Button (Enter). • Use Gray Arrow Buttons to select A19 Fast Update, 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). ```
### A19 Options, RS485 Values, Read/Write Commands, and Formats | Options | Description | RS-485 Value | | ------------ | ----------- | ------------ | | OFF (Custom) | - | 0 | | ON | - | 1 | > Refer to the [Read/Write Memory List](/qr/fu-lt-english-v1/communication/modbus-rtu-protocol/read-write-memory-ram.md) for the Modbus command format. This parameter uses the Int16 data format. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.lorric.com/qr/fu-lt-english-v1/parameters/a-measurement-setup/a19-fast-update.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.