TCP Forwarder
The AnyShake Observer provides a forwarder service that binds to a specific host and port to forward data to other services. This is useful when you want to forward seismic data to other services. The message format is NMEA-like, here is an example:
$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,16993,17047,17064,16975,17011,16985,17024,*63
$AS,SHAKE,00,EHE,1724827695208,100,-396,-409,-404,-369,-389,-366,-390,-386,-373,-400,-404,-371,-386,-401,-390,-381,-390,-390,-389,-385,-391,-398,-388,-390,-399,-408,-395,-393,-416,-406,-391,-396,-397,-398,-395,-378,-373,-401,-389,-393,-403,-400,-407,-375,-387,-382,-369,-407,-410,-396,-384,-382,-417,-420,-388,-404,-419,-402,-404,-412,-404,-414,-397,-397,-395,-395,-388,-399,-395,-423,-385,-399,-406,-404,-396,-406,-392,-400,-401,-370,-419,-410,-390,-403,-379,-406,-413,-394,-379,-394,-392,-413,-367,-380,-399,-394,-415,-365,-390,-381,*CB
$AS,SHAKE,00,EHN,1724827695208,100,140,173,164,154,140,162,168,170,151,171,161,141,164,171,165,162,163,178,159,165,158,169,177,154,164,171,166,162,169,146,166,146,165,153,159,144,154,148,143,161,147,176,141,149,156,145,169,151,161,174,156,132,172,175,139,157,154,160,160,162,164,171,156,156,158,162,132,153,159,166,153,166,169,168,152,182,172,160,150,164,162,167,151,165,152,151,155,154,155,162,155,146,156,163,154,167,158,141,161,147,*2A
Message Format
In the example above, the message is divided into three lines by \r\n, each line starts with $ and ends with a checksum. The message is divided into fields separated by commas.
| Field(s) | Example | Description |
|---|---|---|
| 1 | $AS | Network code |
| 2 | SHAKE | Station code |
| 3 | 00 | Location code |
| 4 | EHZ | Channel code |
| 5 | 1724827695208 | Timestamp in milliseconds |
| 6 | 100 | Sample rate |
| 7-106 | 17005,...,17024 | Samples 0-99 |
| 107 | *63 | Checksum in hexadecimal |
About Checksum
To calculate the message checksum, here are some example codes:
C
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
uint8_t getChecksum(const char* message, size_t len, int* err) {
uint8_t checksum = 0;
*err = 0;
char* fields[len];
int field_count = 0;
// Split the message into fields
char* message_copy = strdup(message);
char* token = strtok(message_copy, ",");
while (token != NULL && field_count < len) {
fields[field_count++] = token;
token = strtok(NULL, ",");
}
// Minimum message fields length is 7 (only 1 sample)
if (field_count < 7) {
*err = 1;
free(message_copy);
return 0;
}
// Convert data fields to int32 and calculate checksum
for (int i = 6; i < field_count - 1; i++) {
int32_t data = atoi(fields[i]);
uint8_t* bytes = (uint8_t*)&data;
for (size_t j = 0; j < sizeof(int32_t); j++) {
checksum ^= bytes[j];
}
}
free(message_copy);
return checksum;
}
int main() {
const char* message =
"$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,"
"17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,"
"17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,"
"17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,"
"17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,"
"17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,"
"17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,"
"17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,"
"17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,"
"16993,17047,17064,16975,17011,16985,17024,*63";
// Find checksum index
const char* checksum_pos = strchr(message, '*');
if (!checksum_pos) {
fprintf(stderr, "Checksum not found in message\n");
return 1;
}
// Parse message checksum
uint8_t msg_checksum;
if (sscanf(checksum_pos + 1, "%2hhx", &msg_checksum) != 1) {
fprintf(stderr, "Failed to parse message checksum\n");
return 1;
}
int err;
uint8_t calc_checksum = getChecksum(message, strlen(message), &err);
if (err) {
fprintf(stderr, "Error calculating checksum\n");
return 1;
}
printf("Message checksum: 0x%02X, Calculated checksum: 0x%02X\n",
msg_checksum, calc_checksum);
return 0;
}
Python
from struct import pack
def get_checksum(message: str) -> int:
fields = message.split(",")
# Minimum message fields length is 7 (only 1 sample)
if len(fields) < 7:
raise ValueError("message fields length is less than 7")
# Convert data fields to int32
data_arr = []
for field in fields[6:-1]:
try:
data = int(field)
except ValueError as e:
raise e
data_arr.append(data)
# Get message checksum by XOR operation
checksum = 0
for data in data_arr:
bytes_data = pack('<i', data) # int32 little-endian format
for byte in bytes_data:
checksum ^= byte
return checksum
def main():
message = "$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,16993,17047,17064,16975,17011,16985,17024,*63"
# Find checksum index
checksum_index = message.find("*")
if checksum_index == -1:
raise ValueError("checksum not found in message")
checksum_index += 1
msg_checksum = int(message[checksum_index:checksum_index+2], 16)
calc_checksum = get_checksum(message)
print(f"Message checksum: 0x{msg_checksum:02X}, Calculated checksum: 0x{calc_checksum:02X}")
if __name__ == "__main__":
main()
JavaScript
function getChecksum(message) {
const fields = message.split(',');
// Minimum message fields length is 7 (only 1 sample)
if (fields.length < 7) {
throw new Error("message fields length is less than 7");
}
// Convert data fields to int32 and calculate checksum
let checksum = 0;
for (let i = 6; i < fields.length - 1; i++) {
let data = parseInt(fields[i], 10);
if (isNaN(data)) {
throw new Error("Invalid data field: " + fields[i]);
}
// Convert int32 to byte array and XOR
let buffer = new ArrayBuffer(4);
let view = new DataView(buffer);
view.setInt32(0, data, true); // little-endian
for (let j = 0; j < 4; j++) {
checksum ^= view.getUint8(j);
}
}
return checksum;
}
function main() {
const message = "$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,16993,17047,17064,16975,17011,16985,17024,*63";
// Find checksum index
const checksumIndex = message.indexOf('*');
if (checksumIndex === -1) {
throw new Error("checksum not found in message");
}
const msgChecksum = parseInt(message.substring(checksumIndex + 1, checksumIndex + 3), 16);
const calcChecksum = getChecksum(message);
console.log(`Message checksum: 0x${msgChecksum.toString(16).toUpperCase()}, Calculated checksum: 0x${calcChecksum.toString(16).toUpperCase()}`);
}
main();
Go
package main
import (
"errors"
"fmt"
"strconv"
"strings"
"unsafe"
)
func getChecksum(message string) (checksum uint8, err error) {
fields := strings.Split(message, ",")
// Minimum message fields length is 7 (only 1 sample)
if len(fields) < 7 {
return 0, errors.New("message fields length is less than 7")
}
// Convert data fields to int32
var dataArr []int32
for _, field := range fields[6 : len(fields)-1] {
data, err := strconv.Atoi(field)
if err != nil {
return 0, err
}
dataArr = append(dataArr, int32(data))
}
// Get message checksum by XOR operation
for _, data := range dataArr {
bytes := (*[4]byte)(unsafe.Pointer(&data))[:]
for j := 0; j < int(unsafe.Sizeof(int32(0))); j++ {
checksum ^= bytes[j]
}
}
return checksum, nil
}
func main() {
message := "$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,16993,17047,17064,16975,17011,16985,17024,*63"
// Find checksum index
checksumIndex := strings.Index(message, "*")
if checksumIndex == -1 {
panic("checksum not found in message")
}
checksumIndex++
msg_checksum, err := strconv.ParseUint(message[checksumIndex:checksumIndex+2], 16, 8)
if err != nil {
panic(err)
}
calc_checksum, err := getChecksum(message)
if err != nil {
panic(err)
}
fmt.Printf("Message checksum: 0x%02X, Calculated checksum: 0x%02X\n", msg_checksum, calc_checksum)
}
Java
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
public class Checksum {
public static int getChecksum(String message) throws Exception {
String[] fields = message.split(",");
// Minimum message fields length is 7 (only 1 sample)
if (fields.length < 7) {
throw new Exception("Message fields length is less than 7");
}
// Convert data fields to int32
List<Integer> dataArr = new ArrayList<>();
for (int i = 6; i < fields.length - 1; i++) {
try {
int data = Integer.parseInt(fields[i]);
dataArr.add(data);
} catch (NumberFormatException e) {
throw new Exception("Failed to parse field to integer", e);
}
}
// Get message checksum by XOR operation
int checksum = 0;
for (int data : dataArr) {
byte[] bytes = ByteBuffer.allocate(4).putInt(data).array();
for (byte b : bytes) {
checksum ^= Byte.toUnsignedInt(b);
}
}
return checksum;
}
public static void main(String[] args) {
String message = "$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,16993,17047,17064,16975,17011,16985,17024,*63";
// Find checksum index
int checksumIndex = message.indexOf("*");
if (checksumIndex == -1) {
throw new RuntimeException("Checksum not found in message");
}
checksumIndex++;
int msgChecksum = Integer.parseInt(message.substring(checksumIndex, checksumIndex + 2), 16);
try {
int calcChecksum = getChecksum(message);
System.out.printf("Message checksum: 0x%02X, Calculated checksum: 0x%02X%n", msgChecksum, calcChecksum);
} catch (Exception e) {
e.printStackTrace();
}
}
}
C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
class Checksum
{
static int GetChecksum(string message)
{
string[] fields = message.Split(',');
// Minimum message fields length is 7 (only 1 sample)
if (fields.Length < 7)
{
throw new Exception("Message fields length is less than 7");
}
// Convert data fields to int32
List<int> dataArr = new List<int>();
for (int i = 6; i < fields.Length - 1; i++)
{
if (int.TryParse(fields[i], out int data))
{
dataArr.Add(data);
}
else
{
throw new Exception("Failed to parse field to integer");
}
}
// Get message checksum by XOR operation
int checksum = 0;
foreach (int data in dataArr)
{
byte[] bytes = BitConverter.GetBytes(data);
for (int j = 0; j < bytes.Length; j++)
{
checksum ^= bytes[j];
}
}
return checksum;
}
static void Main(string[] args)
{
string message = "$AS,SHAKE,00,EHZ,1724827695208,100,17005,17024,16971,17027,17027,17026,17018,16990,17043,16999,16990,17084,17027,16998,17061,17051,17054,17069,17005,17047,17005,17000,17001,16967,16963,17046,16987,17002,17025,16933,16977,16959,16983,17031,16985,17059,16972,16989,17041,17018,16947,17044,16973,17026,17045,17066,17037,16983,17041,17082,16973,17033,17022,16989,17039,17072,17028,17062,16989,17004,17045,17025,16998,17018,17017,17074,17020,17028,17058,16933,17023,17012,16993,17047,17014,17014,17060,17019,17018,17044,16974,17024,17025,17023,17085,17007,17013,17090,17041,17036,17038,17016,17066,16993,17047,17064,16975,17011,16985,17024,*63";
// Find checksum index
int checksumIndex = message.IndexOf('*');
if (checksumIndex == -1)
{
throw new Exception("Checksum not found in message");
}
checksumIndex++;
int msgChecksum = Convert.ToInt32(message.Substring(checksumIndex, 2), 16);
try
{
int calcChecksum = GetChecksum(message);
Console.WriteLine($"Message checksum: 0x{msgChecksum:X2}, Calculated checksum: 0x{calcChecksum:X2}");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}