Tunnel – Advanced example for modbus devices reading and broadcasting to a web platform via a JSON object

Scenario details:

• We have 3 modbus RTU devices. It is recommended that the MTX-Tunnel polls them periodically sending the records to a web platform via a JSON object. The web platform requires login and password authentication
• The MTX-Tunnel must periodically poll, every 2 minutes and via its serial port RS485, the 3 ModBus devices. The records to read are different for each device:
  • Device 1: records 20 to 21 and records 100 to 105
  • Device 2: records 30 to 35
  • Device 3: records 40 to 60
  • Devices 1 and 2 will use the modbus read command 0x03 (the most common). Device 3 will use the modbus read command 0x04.
• Records 20 to 21 of Device 1 must be read and sent to the web platform every 2 minutes. Records 100 to 105 will also be read every 2 minutes but we only want to send them to the web platform every 10 minutes
• Records 30 to 35 of Device 2 will be read every 2 minutes, but they will only be sent to the web platform when the value of one of the records differs by “10” or more from the last record sent
• Records 40 to 60 of Device 3 will be read every 2 minutes. They will be sent to the web platform every 60 minutes but a reading will also be sent if any record differs by “25” or more from the last record sent

Solution: MTX-Tunnel firmware + MTX-Java-IoT/MTX-Java-T/MTX-Java-T2

EXAMPLE of settings (file config.txt) for such scenario:

Configuration

Observations

COMM2_baudrate: 9600 COMM2_bitsperchar: 8 COMM2_autorts: off COMM2_autocts: off COMM2_stopbits: 1 COMM2_parity: none GPRS_apn: movistar.es GPRS_login: MOVISTAR GPRS_password: MOVISTAR GPRS_timeout: 0 MTX_PIN: 0000 MTX_mode: none MTX_model: MTX-4G-JAVA-IOT-STD-N MTX_portAux: modbusmaster MTX_TPProtocol: ntp MTX_TPServer: ntp.roa.es MTX_TPServer2: es.pool.ntp.org MTX_ping: 35 MTX_pingIP: 8.8.8.8 SMS_allPhones: on SMS_sendIP: on SMS_ATEnabled: on SMS_ATResponse: on FIREWALL_enabled: off TELNET_enabled: on TELNET_login: user TELNET_password: 1234 TELNET_port: 20023 LOGGER_enabled: on LOGGER_password: ID00001 LOGGER_server: www.miservidorWeb.com/json.asp?data= LOGGER_registerSize: 300 LOGGER_numRegistersFlash: 1500 LOGGER_serverLogin: miLogin LOGGER_serverPassword: 12345678 LOGGER_httpMode: getjson MODBUS_address: 1;1;2;3 MODBUS_start: 20;100;30;40 MODBUS_numwords: 2;6;6;21 MODBUS_period: 120 MODBUS_readCommand: 3;3;3;4 MODBUS_logFrequency: 1;5;1;30 MODBUS_changeDiff: 0;0;10;25 MODBUS_logType: 0;0;1;2

Serial port baud rate Number of bits No flow control No flow control 1 stop bit No parity APN GPRS from your network operator GPRS Login GPRS Password Modem is always GPRS connected SIM Card PIN MTX-Tunnel mode MTX modem model AUXILIAR COM port used as master modbus Time synch. protocol Time server Backup time server Ping every 35 minutes without comms IP address to ping All phone numbers are authorized IP sent to phone which called or “on” SM Remote AT commands by SMS enabled Modem response to AT command with SMS Any IP will be able to connect to the modem Telnet is activated Telnet login Telnet password Telnet port is 20023 We enable the MTX Logger, to store the records Password field can be used as ID device Server URL, will receive JSON data Register size Maximum number of records in MTX Web platform login The password of the web platform HTTP GET (JSON) mode ModBus addresses of devices to be read Initial addresses of each device Number of records read from each device Frequency of readings in seconds First 2 devices use 0x03 and the other 2 0x04 Device 1 sends variables every 1 and 5 records. Device 3 every 30 records Device 2 controls if record variation is >=10. Device 2 controls if record variation is >=25 Device 1 sends with regards to time. Device 2 sends change in value. Device 3 sends time and/or change in value

Details:

• At the end of the manual you will find how to configure the internal microswitch to activate the RS485 bus of this modem model