UM344-2CALIBRATION AND MAINTENANCE

 

TABLE 6.9 Symptom - Erratic Output

 

 

 

POSSIBLE CAUSE

 

CORRECTIVE ACTION

 

 

 

Loop Wiring

 

Check for 12 Vdc minimum across SIGNAL +/- terminals in transmitter terminal

 

 

compartment.

 

 

Check power supply output voltage: 17 Vdc minimum; 42 Vdc maximum.

 

 

Check for loose loop wiring at power supply terminals, Supply Barriers (if

 

 

used), junction boxes, and transmitter terminal compartment.

 

 

Check for loose leads at Current Sense Resistor.

 

 

Check for accumulation of moisture in transmitter terminal compartment.

 

 

Check for multiple grounds on loop cable shield.

 

 

Check for the proper type of loop cable and for electrical interference between

 

 

the loop cable and any adjacent cables in a cable tray or conduit.

 

 

Check signal loop is grounded, not floating. Ground signal loop at one point

 

 

only, preferably at the power supply negative terminals.

 

 

 

Loop power supply excessively

 

Confirm defective power supply by substituting spare supply for suspect

noisy

 

supply.

 

 

Select a higher damping value (software filter time constant).

High level noise pick-up in sensor

 

Low level leads between sensor and transmitter should be shielded.

leads

 

 

Transmitter Electronics Failure

 

Check transmitter STATUS. If a FAILSAFE message is posted, refer to

 

 

Section 6.3.2.1, paragraph A, for troubleshooting procedures.

 

 

If STATUS is OK, select LOOP OVRD (loop override). Verify loop by setting

 

 

output current to 4, 12 and 20 mA (read on Digital Meter or ammeter connected

 

 

to TEST +/- terminals). Carefully observe that the selected currents remain

 

 

steady.

 

 

If current cannot be set or is unstable, replace the Electronics Module. See

 

 

Section 6.5.

 

 

 

6.3.3 Diagnosing a Defective Digital (LCD) Meter

The optional LCD is functionally tested during a transmitter power up or master reset. It is also tested when the MXC TEST program (transmitter self-diagnostics) is executed. The 4 second test activates all the legends and numerical segments of the LCD. However, if the LCD fails the test, the failure is not reported by the self-diagnostics. The LCD must be observed when performing the MXC TEST program to confirm its test.

If the LCD is not functioning correctly, use an on-hand spare LCD to prove the suspect LCD is defective as follows:

September 1995

6-25

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Siemens UM344-2 user manual Symptom Erratic Output, Diagnosing a Defective Digital LCD Meter
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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.

One of the main features of the Siemens UM344-2 is its high processing speed, which allows for real-time data processing and decision-making. The controller utilizes advanced microprocessor technology, ensuring quick response times and efficient operation. Its architecture supports multitasking, enabling it to manage multiple processes simultaneously without compromising performance.

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.
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