Tunnel – Tunnel 4G-RS232 – Set up the modem as a permanently connected TCP/IP server, with DynDNS and Client Temporal socket enabled

Scenario details:

• There are several devices with an RS232 port which need to be monitored from a Control Centre via 4G
• You must be able to gain access to the RS232 devices. So the modem connected to the device’s serial port must remain continuously connected to 4G, waiting for a connection
• Modems will only accept incoming connections from the IP central office: 200.200.200.200 and will reject any connection coming from different IP addresses
• In order to reduce the cost, SIM cards will use dynamic IP addresses. As there are only a few devices to be controlled, it is not necessary to configure a DNS private server (DNS_enabled: off) and you can just use the DynDNS service
• Central Control station connections will be periodic. Sometimes the devices may send an alarm through the port. In the case of not having a connection available between the PC central control station and the MTX-Tunnel, the MTX-Tunnel must create a temporary connection to another server (same address 200.200.200.200, and port 20011) to report the alarm

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

Config.txt configuration file:

Configuration

Observations

COMM_baudrate: 115200 COMM_bitsperchar: 8 COMM_autocts: off COMM_autorts: off COMM_stopbits: 1 COMM_parity: none GPRS_apn: movistar.es GPRS_login: MOVISTAR GPRS_password: MOVISTAR GPRS_DNS: 8.8.8.8 GPRS_timeout: 0 MTX_PIN: 0000 MTX_model: MTX-4G-JAVA-IOT-STD-N MTX_mode: server MTX_temporalClient: on MTX_urc: off TCP_IP: 200.200.200.200 TCP_port: 20010 FIREWALL_enabled: on FIREWALL_IP1: 200.200.200.200 DYNDNS_enabled: on DYNDNS_server: members.dyndns.org DYNDNS_hostname: mtxtunnel.dyndns.org DYNDNS_login: user DYNDNS_password: myPassword

Serial port baud rate 8 bit data CTS hardware control disabled RTS hardware control disabled 1 stop bit No parity GPRS APN from your network operator GPRS Login GPRS Password Google DNS. Must be used if TCP_IP is set to DNS Value 0 means MTX-Tunnel is always connected If SIM card has no PIN security, use 0000 MTX terminal modem model used TCP server mode Temporal client mode enabled URC messages will not be sent Server IP address used for temporal client mode Used in server and temporal client socket Firewall enabled IP address authorized to connect to MTX-Tunnel DynDNS service enabled DynDNS server URL Your DNS name Your DynDNS account login Your DynDNS password account

Details:

• Compatible with DynDNS & NO-IP. If using NO-IP (which is free) instead of DynDNS, the parameter where we have “members.dyndns.org” should be replaced by “dynupdate.no-ip.com”