Telemetry and Remote Process Monitoring: Industrial Wireless Communication

Industrial telemetry transports data from sensors and field equipment to a central station or supervisory system (SCADA), through wireless links. It reduces civil works costs, allows extending monitoring to remote areas and improves real-time decision making.

1. Typical architecture

• Field sensors and transmitters: Measure the variable and deliver 4-20 mA signal, pulses or digital protocol (Modbus RTU/TCP, HART).
• Remote telemetry unit (RTU): Acquires field signals, digitizes them and transmits them over the wireless link. It can include inputs/outputs, solar or battery supply and local logic.
• Communication link: Radio frequency (licensed or unlicensed), cellular (GPRS/4G/5G), industrial WiFi, LoRa or fiber. The choice depends on distance, topography, network availability and data volume.
• SCADA software / monitoring platform: Centralizes, visualizes, stores history and generates alarms.

MARPATECH represents industrial wireless communication solutions from DataLinc, including redundant wireless radios and serial/ethernet modems that transport industrial protocols reliably and securely.

2. Wireless link technologies

• Licensed frequency radio: Greater range and reliability, requires license. Ideal for high responsibility systems (aqueduct telemetry, pipelines).
• Unlicensed frequency radio (900 MHz / 2.4 GHz / 5.8 GHz): No license required, lower initial cost, but subject to interference and shorter range. Suitable for point-to-point or point-to-multipoint local area links.
• Cellular (GPRS/4G/5G): Uses the existing mobile network; ideal for sites with coverage, sporadic monitoring and lower infrastructure cost.
• WiFi and wireless Ethernet: To interconnect equipment within a plant (local area networks), with high speeds but shorter range.
• LoRa / LPWAN: Low consumption and long range with low data rate, excellent for batteries and periodic readings.

3. Selection criteria

• Distance and topography: Available line of sight, obstacles, antenna heights. The greater the distance and obstacles, the more power or repeaters required.
• Availability and response time: Real-time control requires low latency and high availability; for sporadic monitoring slow updates suffice.
• Determinism: In data control applications (Modbus between PLC/RTU) the link must be deterministic and with predictable times.
• Security: Encryption and authentication to prevent unauthorized access that could manipulate the process.
• Power supply: In remote sites without grid power, solar panels and batteries are used, optimizing equipment consumption.
• Environment: Equipment with IP protection and resistant to site temperature, humidity and vibration.

4. Reliability and redundancy

In critical applications link redundancy is implemented: two radios or two technologies (for example, radio + cellular) that switch automatically on failure. It is complemented with redundant power and properly sized antennas to secure the link. Remote diagnostics of link status (signal strength, quality, failures) is key to keeping the system operational.

Conclusion

Wireless telemetry is an effective and secure solution to monitor process variables in remote locations, provided the link, power and security are correctly sized. A well-designed architecture reduces costs, extends coverage and improves information availability.

MARPATECH SAC represents in Peru, Argentina and Colombia telemetry and industrial communication solutions from DataLinc, advising on the design of reliable wireless links for mining, water, oil and gas and industrial processes.