LSI Storm Front Distance Sensor User Manual

LSI Storm Front Distance Sensor

Revision list

Notes on this manual

The information included in this manual may be modified without notice. No part of this manual may be reproduced in any form or by any electronic or mechanical means, for any use, without LSI LASTEM’s written permission. LSI LASTEM reserves the right to intervene on the product, without the obligation to promptly update this document. Copyright 2017-2022 LSI LASTEM. All rights reserved.

Introduction

The storm front distance sensor is a sensor capable of providing an estimate of the distance of the storm front in a radius of about 40 km from the place where it is installed. Through a sensitive RF receiver and an integrated proprietary algorithm, the sensor can detect discharges both between clouds and earth and between clouds and clouds, eliminating the interference caused by artificial signals such as motors and microwave ovens. The estimated distance does not represent the distance of a single lightning bolt, but the distance from the line of the storm front.

Technical specifications

Models

Code| DQA601.1| DQA601.2| DQA601.3

DQA601A.3

---|---|---|---
Output| RS-232| USB| TTL-UART
Compatibility| Alpha-Log| PC (Terminal Emulation program)| MSB
Connector| DB9-DTE| USB type A| Free wires

Technical specifications

•  DYA032 arm and DYA049 collar on pole (diam. 45 ÷ 65 mm)
• On DYA046 bar

Accessories

Installation and configuration

Installation

Choosing the right site is essential for the effective operation of the storm front distance sensor. It should be free from noise-generating equipment such as electromagnetic fields. These could be a source of noise, causing the sensor to provide incorrect measurements. Below are the sources of noise to avoid:

• Inductor based DC-DC converters
• Smartphone and smartwatch display

Once the site has been identified, connect the sensor to the LSI LASTEM Alpha- Log data logger or directly to a PC, depending on the type of electrical connection (USB, RS-232 or TTL-UART).

Use with Alpha-Log

DQA601.1, DQA601.3 and DQA601A.3 can be used with Alpha-Log, if properly configured. For the configuration of the data logger, proceed as follows:

1. Launch the 3DOM software.
2. Open the current configuration in the data logger.
3. Add the sensor by selecting its code (e.g. DQA601.1) from the 3DOM Sensor Library.
4. Add the proposed input type.
5. Set the parameters related to the measurements produced.
6. Where:

  *  **Communication port:** is Alpha-Log’s serial port where the sensor is connected.
  *  **Mode:** is the sensor operation mode. Select Internal or External depending on where it is installed.
  * Number of lightning strikes per signal: it is the minimum number of electric shocks needed to determine the distance of the storm front.
2. For more information on sensor configuration, refer to §3.2.

6. If you want to change some parameter, such as measure name or acquisition installment, open the measure you just added.
7. Then, select the tabs of interest to display their parameters.
8. Save the configuration and send it to the data logger.

More information about the configuration can be found in the Alpha-Log manual.

To connect the sensor to the data logger, please use the following tables

DQA601.1 (RS-232)| | DQA601.3 (TTL-UART)| Alpha- Log| | DQA601A.3 (TTL-UART)| Alpha- Log
---|---|---|---|---|---|---
Pin| Signal| Filo| Signal| Terminal| Filo| Signal| Terminal
2| Rx| Green| Rx| 20| Brown| Rx (TTL)| 20
3| Tx| Red| Tx| 19| Green| Tx (TTL)| 19
5| GND| Blue| GND| 21| White| GND| 21
9| Power 5 ÷ 24

Vdc

| Brown| Power 5 ÷ 24

Vdc

| 22| Yellow| Power 5 ÷ 24

Vdc

| 22
| Shield| Shield| 30| Shield| Shield| 30

DQA601.1 has DB9 serial connector, so it can be connected directly to the RS-232 COM2 serial port. Models DQA601.3 and DQA601A.3 have free wire connection. They should be connected to the 19-20-21-22 terminals of the TTL COM4 serial port.

For more information on the signals, refer to the respective drawings supplied with the product

• DQA601.1: DISACC210137
• DQA601.3: DISACC210156
• DQA601A.3: DISACC210147

Use with the PC

DQA601.2 can be connected to a PC via the USB port. Proceed as follows:

1. Connect the sensor to the PC and identify the serial port assigned to it.
2. Start a terminal emulation program (e.g. Realterm), choose the serial port to which the sensor is connected and set the communication parameters as follows:

• Speed: 9600 bps
• Data bits: 8
• Parity: None
• Stop bits: 1
• Flow control: None

When communication is established, the terminal program will begin to display the information sent spontaneously by the sensor.

For more information about communication with the sensor, refer to Chapter 4.

Sensor configuration

The sensor comes with a standard configuration. However, through a terminal emulation program installed on a PC, you can change some operating parameters. Commands and parameters are described in §4.3

SAP Communication Protocol

The sensor implements SAP (Simple ASCII Protocol), the proprietary communication protocol of LSI LASTEM that provides the services of configuration, diagnostics and transfer of the data measured by the sensor.

The sensor supports two ways of sending data:

• on demand
• spontaneous

“On-demand” mode is the one set by default, in which the master part (applicant) interrogates the sensor via the MIV command; alternatively, the “spontaneous” mode is available, with which the sensor autonomously transmits messages related to particular events concerning the measurements made.

The following table summarizes the events reported by the “spontaneous” mode

Messages format

Messages are carried by plots where the beginning of the message is the character ‘!’ or ‘$’ and the term is identified by the character ASCII CR (Carriage Return); the ASCII character LF (Line Feed) can optionally follow CR, for terminal display reasons, but is in any case ignored during reception; during transmission it is always transmitted after CR.

The message start character ‘!’ is used to simplify communication that takes place via a terminal emulation program. When you want to have more security or use a communication bus where multiple devices are connected, the message start character is ‘$’ and the plot will have more device address and checksum fields. If an error condition is identified by the slave, it produces a response with an error identification code, or it does not respond at all when the packet is not decoded in its entirety (e.g. the terminal part is missing); if the packet is received incorrectly by the master part or not received in the expected time (timeout), the latter may send the slave a retransmission request command; the sending party of the retransmission command regulates the number of maximum attempts through which this operation is repeated; the receiving party does not limit the number of attempts received and consequently managed.

In summary, for manual terminal communications (or point-to-point)

In case of communication produced between a master and one or more slaves (point to multipoint)

The address fields dd and ss are two-digit ASCII numbers, making it possible to address up to 99 different units; the value “00” is intended as a response to the master unit, while the value “–” indicates a broadcast message, intended for any apparatus connected to the master; the broadcast message is not followed by any response by the receiving slave units.

The control field c is used to manage data flow and can take the following values

The field of control (checksum) is calculated using the algorithm CCITT CRC16 (polynomial X^16 + X^12 + X^5 + 1) of the characters starting from the one after the message header (! or $) and ending at the character immediately preceding the checksum field itself. The start value of the calculation is zero. To test the CRC calculation, you can send the test command:

• $0100.DPV46FD[CR][LF] (CRC = 0x46FD)

to which the instrument (ID = 01) responds with a message like this

• $0001.DPV1.00.00EA78[CR][LF] (CRC = 0xEA78)

The cmd command code consists of three characters. It is not case sensitive, so for example the DPV and dpv commands for the instrument are equivalent. The transmission of data that, by volume, cannot be packed in a single message, is done by specifying the control byte c according to the following rules:

• Data transported in a single message: the control byte is period;
• Data carried in more than one message: the control byte can be comma or period; upon receipt of the message containing the control byte comma, the receiving party must send the message ‘+’ to indicate to the transmitter the possibility of transmitting the next part of the data; upon receiving the message with control byte period, the receiving party may refrain from replying (if the reception was correct), because sending a subsequent message ‘+’ results in the return of a message containing the error code NoMoreData.

A specific limit is not imposed on the number of messages into which the data part is divided; for performance issues on some lines of communication, particularly slow or high risk of interference (typically via radio), the data transmitted in each message should be relatively small in size, so the whole data set is, in this case, divided into more messages. The maximum size of the transmitted data in each message is an editable system parameter (SMS command).

The functions set out in the communication protocol are

• Commands to regulate communication.
• Commands to manage the configuration.
• Diagnostic commands.
• Commands to read the measured data.
• System management commands.

Commands to regulate the communication

The commands in the table do not generate any response.

Code| Parameter

type

| Description
---|---|---
OKs| –| OK : response message, without return data part, positive confirmation of the previous command received ( s indicates space )
ERs| num| Error : response message as a negative confirmation of the received request; the

error status code is indicated by num in the response message ( s indicates space )

In general, for all commands that allow the setting of a parameter, if this is not specified in the request message (the field is left completely empty), the response that the slave unit produces indicates the value of the parameter itself currently stored (reading of parameter).

The error states returned by the ER message are identified by the following table

The payload part of the message is typically charged to the application level of the protocol which interprets the received data and formats the data to be transmitted. While formatting data, these rules are followed when possible:

• Several parameters (both request and response) are separated by the space character; some answers, for clarity when the values are numerous and heterogeneous from the semantic point of view, use tags in the tag:value format.
• The date and time are expressed in ISO 8601 format; normally the instrument expresses the time internally, in transmissions and in GMT-related files; the durations are expressed in the format “gg hh:mm:ss”.
• Logical states:
  • “Y”, “YES”, “1”, “TRUE”, “ON” for true value
  • “N”, “NO”, “0”, “FALSE”, “OFF” for false value
• Integers: decimal places in number dependent on the number of bits dedicated to the variable to contain the data
• Floating point values:
  • Decimal separator: period
  • Decimal places: dependent on the transmitted value; when appropriate, the scientific format is used (mantissa exponent)

Commands to manage the configuration

Code| Parameter

type

| Description
---|---|---
CWM| Integer| Config Working Mode : operating mode of the sensor.

Allowed values: 0=Indoor, 1=Outdoor. Default value: 1

CNL| Integer| Config Number Lightning : number of electric discharges needed to let the sensor to calculate the thunderstorm distance; if greater than 1 let the sensor to ignores sporadic discharges detected in short time, thus avoiding false lightning detections.

Allowed values: 1, 5, 9, 16. Default value: 1

CLA| Integer| Config Lightning Absence : corresponds to the time, in minutes, in which the absence of detection of electrical discharges determines the return of the system to the condition of absence of lightning (100 km).

Allowed values: 0 ÷ 255. Default value: 20

CNF| Integer| Config Noise Floor : filter adjustment threshold for background noise; higher values determine a reduction in sensitivity to lightning detection; if you want to set this parameter in a fixed way, verify that the CAN parameter is set to false.

Allowed values: 0 ÷ 7. Default value: 2

CAN| Boolean| Config Auto Noise floor : enabling automatic calculation of the filter adjustment threshold for background noise; the most recent calculated value can be read with the CNF command.

Allowed values: true, false. Default value: true

CWT| Integer| Config Watchdog Threshold : sets the s ensitivity of the sensor to electrical discharges on a scale of 0 ÷ 15; higher is this value, and lower is the sensor sensitivity to the discharges, therefore greater is the risk of not detecting discharges; lower is this value, higher is the sensitivity of the sensor, therefore greater is the risk of false

readings due to background discharges and not due to real lightning strikes; this

| | parameter is active only when the Auto watchdog threshold parameter is set to

false.

Allowed values: 0 ÷ 15. Default value: 2

---|---|---
CAW| Boolean| Config Auto Watchdog threshold : determines an automatic sensitivity of the sensor with respect to the detected background noise; when this parameter is set to true it determines that the sensor ignores the value set in the Watchdog threshold parameter. The most recent calculated value can be read with the CWT command.

Allowed values: true, false. Default value: true.

CSR| Integer| Config Spike Rejection : sets the sensor’s ability to accept or reject false electric discharges not due to lightning strikes; this parameter is additional to the Watchdog threshold parameter and allows to set an additional filtering system to unwanted electrical discharges; the parameter has a scale from 0 to 15; a low value determines a lower ability of the sensor to reject false signals, therefore it determines a greater sensitivity of the sensor to disturbances; in the case of installations in areas without disturbance it is possible / advisable to increase this value.

Allowed values: 0 ÷ 15. Default value: 2

CMD| Boolean| Config Mask Disturbance : determines whether noise masking is active; if set to true , the sensor does not provide an indication (on trace log, see DET command) of disturbance if it determines its presence.

Allowed values: true, false. Default value: false.

CRS| Boolean| Config Reset Statistic : the true value disables the statistical calculation system inside the sensor which determines the distance from the storm front considering a series of lightning strikes; this determines that the distance calculation is made only considering the last single electrical discharge measured.

Allowed values: true, false. Default value: false.

CSV| –| Config SaVe : saves the configuration parameters in the sensor memory.
CLD| –| Config LoaD : loads the configuration parameters from the sensor memory.
CPM| Boolean| Config Push Mode : enable/disable the spontaneous sending mode ( push mode ) of bthe measurement events.

Commands relating to measurements

Code| Parameter

type

| Description
---|---|---
MIV| –| Measures Instant Value: requests the value of the distance from the temporal front calculated on the basis of the electrical discharge measurements.

Answer: float value (km)

MRD| –| Measures Reset Distance : set the value of the last detected distance of the storm

front to the distance value Not Defined

Diagnostic commands

Code| Parameter

type

| Description
---|---|---
DET| Boolean| Diagnostic Enable Trace log
DPV| Boolean| Diagnostic Progam Version : returns the current firmware version on the sensor
DFR| –| Diagnostic Full Report : provides as an answer a set of values indicating the internal state of operation. They are:

• ATE : error state of antenna tuning algorithm (Y/N);

| | Answer: ATE:boolean value

• RCE : error state of the calibration algorithm RCO (Y/N); Answer: RCE:boolean value
• ATF : antenna tuning frequency (nominal 500 kHz); Answer: ATF:integer value
• ATRV : register value used for antenna tuning; Answer: ATRV:integer value
• NFL : background noise level set manually (CNF command) or automatically adjusted (CAN command);
• Answer: NFL:whole value
• WT : the threshold value of the watchdog set manually (CWT command) or automatically adjusted (CAW command);
• Answer: WT:whole value
• SRL : manually set noise rejection value (CSR command); Answer: SRL:full value
• LL : time elapsed since the last lightning detected warning (seconds); Answer: LL:integer value
• LD : time elapsed since the last detected noise report (seconds); Answer: LD:integer value
• LN : time elapsed since last detected background noise (seconds); Answer: LN:integer value

---|---|---

Sample communications

To clarify the different possible combinations of messages exchanged between master and slave, some explanatory examples follow.

indication of other messages to follow

–| !.ER xx\r| Slave indicates that the command does not support the communication

flow control that has been indicated by master

front = 5 km); in case of an absent or unidentified storm front, the sensor sends

the value 100 (see the CLA configuration parameter).

Disposal

This product is a high electronic content device. In accordance with environmental protection and recovery regulations, LSI LASTEM recommends treating the product as a waste of electrical and electronic equipment (RAEE). Its collection at the end of its life must be separated from other waste. LSI LASTEM is responsible for the conformity of the production, sale and disposal chain of the product, ensuring the rights of the user. Improper disposal of this product will result in law penalties.

Contacting LSI LASTEM

LSI LASTEM offers its assistance service at support@lsi-lastem.com, or by filling out the Request for technical assistance module, downloadable from www.lsi-lastem.com.

See the following addresses for more information

• Telephone number: +39 02 95.414.1 (switchboard)
• Address: Via ex S.P. 161 – Dosso n. 9 – 20049 Settala, Milano
• Website: www.lsi-lastem.com
• Post-sale service: support@lsi-lastem.com,
• Repairs: riparazioni@lsi-lastem.com

References

• lastem.com
• Environmental Monitoring Solutions - LSI LASTEM

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