Flowserve MX HART Field Unit - Manual (Page 8)

MX/QX HART Field Unit FCD LMENIM2340-00 – 1/14
8
Commands to the unit come over the network from the host system, which may be:
• Personal Computer (PC)
• Distributed Control System (DCS)
• Programmable Logic Controller (PLC)
• Field Device Tool (FDT) w/Device Type Manager (DTM)
• Some other microprocessor-based device
A HART field device is an intelligent device within the actuator that can send multiple digital device variables to the
control system over a 4-20 mADC analog signal loop. The device provides control and self-test capabilities, which allow
abnormal conditions to be easily and immediately identified before an unplanned shutdown occurs.
Additional features and capabilities are:
• The system reduces the cost of wiring and installation – existing wiring and multi-drop connections can be used.
• The devices are interoperable – devices from different suppliers can communicate with one another on the same
network.
1.5.1 General Network Specification
System Specifications:
Communications using the HART Communication Foundation Protocol
Network Specificationss:
• Point-to-point and multi-drop topologies
• Master/slave communication
• Simultaneous 1200 bps digital communication without 4-20 mADC signal interruption
• Up to two masters per network (primary and secondary)
• Burst mode for continuous message broadcasting
MX/QX HART Unit Specification:
The field unit mounts in the actuator and is software-controlled in order to allow functionality of:
• Dynamic Variables PV, SV, QV and TV
• Device Variables: Position Setpoint, Measured Position, Torque, Motor Temperature and Compartment Temperature
• Network Communication
• Device-Specific Commands
System Host Specifications:
The HART master is the network system host, and can be a personal computer (PC), distributed control system (DCS),
programmable logic controller (PLC), or another microprocessor-based device. The HART protocol allows for up to
two masters (primary and secondary) per network loop. Secondary masters, such as handheld communicators, can be
used without interrupting communications between the primary master and field devices.