INSTALLATION

UM344-2

Power supply output voltage must be less than the calculated value. The maximum voltage across the input terminals of a Transmitter should never exceed 42 volts.

The maximum number of Transmitters that can be connected to a Multi-Drop Network is fifteen. Each Transmitter is "parked" in a low current draw mode (4 mA) to conserve power. Ensure that the network power supply is capable of sourcing the total current consumed by the number of transmitters on the Network.

4.3.5 Cable Capacitance and Maximum Length

A cable length calculation is necessary when HART communication is to be employed. Cable capacitance directly affects maximum Network length.

4.3.5.1 Cable Capacitance

Cable type, conductor size, and recommended cable model numbers are stated in Section 8.3.3 Two-Wire Cable.

Cable capacitance is a parameter used in the calculation of the maximum length of cable that can be used to construct the Network. The lower the cable capacitance the longer the Network can be. Manufacturers typically list two capacitance values for an instrumentation cable:

1.Capacitance between the two conductors.

2.Capacitance between one conductor and the other conductor(s) connected to shield. This capacitance is the worst case value and is to be used in the cable length formula.

4.3.5.2 Maximum Cable Length Calculation

The maximum permissible single -pair cable length is 10,000 feet (3000 meters) or less as determined by the following formula:

65,000,000 Cf + 10,000

L =

 

-

 

R x C

C

 

 

Formula Definitions:

L:The maximum total length of cable permitted to construct the Network. L = Feet when C is in pF/ft. L = meters when C is in pF/meter.

R:The Network Resistance which is the ohmic sum of the Current Sense Resistance and Barrier Resistance (both Return and Supply), if any, in the Network and the resistance of the wire.

4-10

September 1995

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Siemens UM344-2 user manual Cable Capacitance and Maximum Length, Maximum Cable Length Calculation

UM344-2 specifications

The Siemens UM344-2 is a cutting-edge industrial controller designed to meet the demands of modern automation and control systems. This powerful device is specifically developed for use in various applications, including manufacturing, process control, and machinery integration. The UM344-2 stands out for its versatility and robust performance in harsh industrial environments.

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The UM344-2 features a modular design, which provides flexibility in configuration and scalability. Users can easily add or remove modules to tailor the system to specific application requirements. This adaptability is beneficial for businesses that need to scale their operations or adjust to changing production demands. The controller is compatible with a variety of I/O modules, allowing for seamless integration with other equipment and systems.

In terms of connectivity, the Siemens UM344-2 supports various communication protocols, including Profibus, Profinet, and Ethernet. This versatility ensures smooth data exchange between the controller and other devices in the automation ecosystem, facilitating comprehensive monitoring and control. The inclusion of these communication standards enhances interoperability and allows for the integration of legacy systems with newer technology.

The Siemens UM344-2 is equipped with advanced diagnostic tools, which enable users to monitor system performance and detect potential issues in real-time. This feature reduces downtime and maintenance costs by allowing for proactive management of the system. The controller also supports remote access capabilities, enabling technicians to troubleshoot and configure systems from off-site locations.

Safety is a critical consideration in industrial environments, and the UM344-2 is designed with this in mind. It incorporates safety-certified features, ensuring compliance with international safety standards. Users can implement safety functions directly within the controller, streamlining system design and reducing the need for external safety components.

Overall, the Siemens UM344-2 exemplifies the fusion of technology and practical application, making it an essential component for businesses looking to enhance their automation processes. With its high performance, flexibility, and focus on safety, the UM344-2 is a reliable choice for industries aiming for efficiency and innovation in their operations.