Example scenario details:

  • The aim is to periodically take readings from an electric meter (every 10 minutes). As readings will be taken often, the meter will be accessed via GPRS instead of GSM calls in order to cut costs.
  • At the same time, the operator energy (Endesa, Iberdrola, …) will make a conventional GSM data call once a day to read the meter.
  • The GSM call must have priority. When the modem receives a call from the energy operator, the GPRS will be “frozen” to make way for the operator. Once the GSM call has finished, the GPRS connection will be re-established.

Proposed solution with  MTX-65i + MTXTunnel

MTXTunnel configuration file for the proposed solution above:

You have to enter this into the modem’s configuration file to be able to run the application as described in the scenario:

COMM_baudrate: 9600 Serial port and energy meter speed
COMM_bitsperchar: 8 Number of data bits
COMM_autorts: off No flow control
COMM_autocts: off No flow control
COMM_stopbits: 1 1 stop bit
COMM_parity: none No parity
 
GPRS_apn: movistar.es GPRS APN provided by GSM operator
GPRS_login: MOVISTAR GPRS Login provided by GSM operator
GPRS_password: MOVISTAR GPRS Password provided by GSM operator
GPRS_timeout: 0 The modem will be permanently connected
 
MTX_mode: server Server type GPRS connection
MTX_model: MTX65i Modem’s model
MTX_ping: 35 Ping time for monitoring connection
MTX_pingIP: 8.8.8.8 Google’s IP (e.g.) to perform the pìng 
MTX_radioBand: europe European GSM band
MTX_rssiLevel: 10 Displays red LED if there is low coverage
 
TCP_port: 20010 TCP port to establish GPRS-Serial gateway
 
Firewall_enabled: off Firewall deactivated
 
CSD_enabled: on Can receive GSM data calls from the energy operator (Iberdrola, Endesa, …)

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Example scenario details:

  • In this current scenario the modem has two serial ports. The energy meter is connected to one serial port, the PLC is connected to the other one.
  • When there isn’t a GPRS connection with the modem or a GSM call established from the operator, the modem has to act as a serial gateway, i.e. all of the data that arrives at the modem from the PLC is redirected to the energy meter and vice versa, all serial data sent to the energy meter should be forwarded to the PLC.
  • 2 GPRS-serial gateways should be established and working at the same time. Through one you will have access to the energy meter to periodically take readings, through the other you will be able to access the PLC’s modbus registers.
  • Additionally, the power operator (Iberdrola, Endesa, …) will make a daily GSM call to read the meter’s data. This GSM call will be given priority, freezing GPRS connections until it is finished.

Proposed  solution with  MTX-65i + MTXTunnel

MTXTunnel configuration file for the proposed solution above: 

You have to enter this into the modem’s configuration file to be able to run the application as described in the scenario:

COMM_baudrate: 9600 Serial port and energy meter speed
COMM_bitsperchar: 8 Number of data bits
COMM_autorts: off No flow control
COMM_autocts: off No flow control
COMM_stopbits: 1 1 stop bit
COMM_parity: none No parity
COMM2_baudrate: 9600 Serial port and PLC speed
COMM2_bitsperchar: 8 Number of data bits
COMM2_autorts: off No flow control
COMM2_autocts: off No flow control
COMM2_stopbits: 1 1 stop bit
COMM2_parity: none No parity
GPRS_apn: movistar.es GPRS APN provided by GSM operator
GPRS_login: MOVISTAR GPRS Login provided by GSM operator
GPRS_password: MOVISTAR GPRS Password provided by GSM operator
GPRS_timeout: 0 The modem will be permanently connected
MTX_mode: server Server type GRPS connection
MTX_model: MTX65i Modem’s model
MTX_ping: 35 Ping time for monitoring connection
MTX_pingIP: 8.8.8.8 Google IP (e.g.) for Ping
MTX_radioBand: europe European GSM bands
MTX_portAux: gateway It enables the serial gateway between the modem’s serial ports when there are no external (GPRS/GSM) connections
TCP_port: 20010 TCP port for establishing GPRS-serial gateway
Firewall_enabled: off Firewall deactivated
CSD_enabled: on Able to receive GSM data calls from the energy operator (Iberdrola, Endesa, …)
Telnet_enabled: on Telnet is enabled for use as a secondary gateway from access to the PLC
Telnet_port: 20011 TCP port receives connections to access PLC (secondary GPRS-serial gateway)
Telnet_bypass: on “on” to use Telnet as a secondary gateway

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