Temperature Monitoring on PID loop at Steel Process


ISA 100 WirelessDirect Reduction Iron (DRI) is one of the processes to reduce oxygen from iron oxide pellets for steel plant. More than 90% of DRI processes use heated LNG as process gas where PID control for temperature or interlock control is of vital importance.


Direct Reduction Iron

Requirement and Background

Reliable temperature measurement without frequent cable replacement is needed.

One of the major problems faced by the user is frequent replacements of cables as those gets degrade faster because of high ambient temperature and process vibrations. These cable replacements increases the operational cost as well as cost of man hours.


Temperature measurement over the radio as part of PID control loops, Interlock control loops and monitoring at DRI process were introduced. (For shaft furnace, gas reformer and other process pipes)

Highly reliable and full redundant wireless system realized this control loop application.

Two pairs of Redundant Access Point YFGW510 with a Duocast1 wireless communication were connected to a pair of Redundant Management Station YFGW410. Redundant Modbus TCP interface for non-Yokogawa DCS2 achieved stress free interoperability.


The installation was completed in 2013 and the measured results for 120 temperature inputs were found satisfactory.

In dense area, out of line of sight devices up to 50m communicated successfully with less than 5% Packet Error Rate.


  • Higher uptime of process
  • Operational cost reduction
  • Risk reduction: cable degradation, noise interference
  • Less installation costs and time: wiring, cable rack, junction box and etc.
Duocast System


This result proved that Yokogawa's high reliable wireless is very effective for DRI process. Deterministic routing algorism makes the communication latency shortest and fully redundant system with Duocast1 system can provide robust control loops. The High Performance "Radio Chip" embedded in these wireless devices helps to achieve High Quality Communications even in dense areas.

After 12 months or more operation, now the customer is considering expanding wireless applications in their site.

  1. Duocast: wireless redundant communication system standardized at ISA100 wirelessTM on double active access points with minimum wireless latency.
  2. The Yokogawa's CENTUM VP R5 or later supports dual-redundant network configuration with YFGW410 field wireless management station. It enables entire system full redundant. Please consult Yokogawa regional sales in case of engaging full redundant ISA100 wireless network system with 3rd party DCS.



  • Iron & Steel

    • Iron and steel industry
    • Improve quality of products, manufacturing, and operation technologies
    • Address environmental and energy-efficiency issues
    • Create the ideal plant and evolve for mutual growth
    See More

Related Products & Solutions

  • YFGW410 Field Wireless Management Station

    YFGW410 Field Wireless Management Station has system manager/security manager/gateway function based on ISA100.11a, and combining this with Field Wireless Access Point(YFGW510) and/or Field Wireless Media Converter(YFGW610) composes the field wireless system.

    See More
  • YFGW510 Field Wireless Access Point

    YFGW510 Field Wireless Access Poin has backbone router function based on ISA, and combining this with Field Wireless Management Station (YFGW410) and/or Field Wireless Media Converter (YFGW610) composes the field wireless system.

    See More
  • YFGW520 Field Wireless Access Point

    YFGW520 Field Wireless Access Poin has backbone router function based on ISA, and combining this with Field Wireless Management Station (YFGW410) and/or Field Wireless Media Converter (YFGW610) composes the field wireless system.

    See More
  • YTA510 Wireless Temperature Transmitter

    The high performance temperature transmitter YTA510 accepts Thermocouple, RTD, ohms or DC mill volt inputs. The transmitters transmit not only process variables but also the setting parameters using wireless signal. The transmitters run on internal batteries, and the installation cost can be decreased since hard-wiring is not required. The communication is based on ISA100.11a protocol specifications. 

    See More
  • YTMX580 Multi-Input Temperature Transmitter

    YTMX580 can accept inputs from up to 8 points of measurement such as thermocouples (8 types: K, E, J, etc.) or RTD signals (3 types: Pt100, etc.), converting the corresponding measurement input values to a wireless signal. It can also accept DC voltage, resistance, and 4 to 20 mA DC signal input.

    See More
  • Field Wireless

    • Flexible wireless solutions
    • Enables less investment in infrastructure
    • Provides greater insights into plant operations
    See More

Have Questions?

Contact a Yokogawa Expert to learn how we can help you solve your challenges.