Suchen Sie etwas anderes?
Scenario details:
- We have a series of old PLCs that use a GSM modem to make and receive conventional GSM calls
- We intend to replace the old GSM based communication system with one using 4G communications, modifying the previous system as little as possible. That is, without modifying the PLC software and modifying the server PC software as little as possible. Each PLC must be able to make calls, like until now, and must be able to receive them, but instead of making GSM calls, they will be IP (4G) connections. That is, it will only be necessary to replace the PLC current GSM modem with an MTX modem + MTX-Tunnel. It will also be necessary to replace the GSM modem connected to the PC server with a TCP/RS232 software converser
- For this, the MTX modem behaves as follows: To emulate the reception of GSM calls the modem remains in listen mode in a TCP port. For this application the chosen port is TCP 20010. When it receives a 2G/3G connection against that TCP port, the MTX modem must set a 2G/3G/4GSerial gateway the same way it would with a GSM conventional call. On the other hand, it must also be possible to establish a 2G/3G connection from the PLC emulating a GSM call. To do this, the PLC will send the typical connection command GSM ATD xxx.xxx.xxx.xxx (as if it was a GSM call but specifying an IP or DNS address instead of a phone number). The MTX-Tunnel must also be connected to this address via the 20010 port
- The PLC will control the DTR modem line, disconnecting 2G/3G/4G communications with that line. The modem will send CONNECT when setting/receiving a connection and NO CARRIER when this ends
Solution: MTX-Tunnel firmware + MTX-Java-IoT/MTX-Java-T/MTX-Java-T2
EXAMPLE of settings (file config.txt) for this scenario:
| Configuration | Observations |
| COMM_baudrate: 9600 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_timeout: 10 MTX_PIN: 0000 MTX_mode: server MTX_model: MTX-4G-JAVA-IOT-STD-N MTX_ping: 35 MTX_pingIP: 8.8.8.8 MTX_radioBand: europe MTX_ATMux: modem MTX_urc: modem MTX_DTR: modem TCP_port: 20010 |
Serial port baud rate 8 bit data No flow control No flow control 1 stop bit No parity GPRS APN by GSM operator GPRS Login GPRS Password A value >5 is compulsory for this scenario If SIM card does not have PIN, leave as 0000 Working mode is TCP server MTX model Ping every 35 minutes without comms IP address to ping Not necessary if the MTX is installed in Europe Compulsory mode for this scenario Compulsory to receive CONNECT and NO CARRIER Compulsory for this scenario Minimum stop with no data to be a new frame |
Enter the “ethernet” or “modem” connection type:
For an ethernet configuration, make sure the IP parameters are compatible with server access according to the concentrator local network configuration. For an ethernet connection, the configuration must be compatible with the concentrator’s local network topology so that it can access the servers. This configuration is done from the “Networks” configuration page (see section 3.2.2.3: “Networks”).
For a modem connection, the modem configuration must be correct before a connection can be set up. This configuration is done from the “Modem” configuration page (see section 3.2.2.4: “Modem”).
The parameters for the servers to be configured are at least the following:
Therefore the following fields need to be configured: “Interface”, “Type”, “Server type”, “Address”, “Port”, “Login” and “Password”.
The other fields can be left at the default values subject to the directories having been properly created beforehand. See section 3.1.2: “Configuration files” for more details.
Wait. The concentrator will reboot using its factory configuration.
