Document: LT0273

MX4428 MXP Engineering / Technical Manual

 

MXP Technical Description

 

 

7.2

CIRCUIT DESCRIPTION

7.2.1BLOCK DIAGRAM

A block diagram of the MXP is given in Figure 7.1.

The MXP can be divided into 4 sections:

(i)The microprocessor and memory. This is the "heart" of the MXP.

(ii)The power supply. The power supply produces the 40V isolated supply for the Analogue Loop and also the 5V isolated supply for the microprocessor.

(iii)The MX4428 Loop Interface. The Loop Interface contains the connect, disconnect circuitry for the MX4428 Loop Power Supply and also the serial data driver circuits.

(iv)The Analogue Loop Interface. This section contains the Loop Driver/ Receiver circuit and the Loop Isolator circuits.

7.2.2MICROPROCESSOR & LOGIC CIRCUITRY

The MXP is controlled by the 68302 Microprocessor CPU (U1). Connected to the CPU bus is the FLASH (U2) which contains the MXP software, and the RAM (U3 and U4) which is used for storing parameters and data associated with devices on the Analogue Loop.

The 68302 includes a communications processor with 3 serial ports. These are used for the 2 responder loop ports and a diagnostic port.

To reduce the number of components on the PCB, a PAL (Programmable Array Logic) (U5) is used to generate bus signals such as RD-, L WR-, and U WR-. It also drives the status LED and is used to read some of the DIP switches.

Both the FLASH (U2) and PAL (U5) are factory programmed for use in the MXP. However the FLASH (U2) can easily be reprogrammed in the field.

7.2.2.1Power On Reset & Watchdog Circuits

The power on reset consists of the DS1232 (U6), which drives the RST signal to the CPU low when the 5V supply is below 4.6 Volts. This ensures that the CPU does not corrupt the RAM when the 5V supply collapses, and the CPU starts up reliably when the 5V supply turns on. The DS1232 also includes a Watchdog circuit inside, to produce a RESET if the CPU stops running properly.

7.2.2.2Memory

Memory addresses are decoded by the MC68302. When first powered up the FLASH occupies the bottom 8k bytes. However the software relocates the FLASH so that the memory addressing is as follows -

000000

- 03ffff

RAM

 

400000

- 47ffff

FLASH

via PAL

800000

-

80000f

LED and SWITCHES

f00000

-

f00fff

INTERNAL RAM AND

PERIPHERALS

The RAM memory and PAL chip are powered by the +5VB supply, which has a supercap (C68) to supply power when the MXP is powered down. This allows the MXP to retain its RAM memory contents for typically 10 hours on MXP power down.

Issue 1.5

24 March 2006

Page 7-3

Page 87
Image 87
Tyco MX4428 Circuit Description, Block Diagram, Microprocessor & Logic Circuitry, Power On Reset & Watchdog Circuits

MX4428 specifications

The Tyco MX4428 is a cutting-edge device known for its robust performance in the realm of wireless communication and sensor acquisition. Tailored for applications in various sectors, the MX4428 is particularly well-suited for industrial automation, environmental monitoring, and smart city initiatives. With its advanced features, the device has gained tremendous popularity among engineers and developers looking for reliability and efficiency in data transmission.

One of the standout features of the MX4428 is its exceptional range, which can extend up to several kilometers under optimal conditions. This long-range capability ensures that data can be transmitted over vast distances without degradation in quality, making it ideal for remote monitoring applications. Additionally, the device operates on multiple frequency bands, providing flexibility in deployment based on specific regional requirements and regulatory guidelines.

The MX4428 utilizes a highly efficient radio protocol that enhances data throughput while reducing power consumption. This asymmetric data transmission method allows for low-duty cycle operation, extending battery life and autonomy. The device's energy efficiency is particularly beneficial in applications where frequent battery replacement would be impractical, such as in environmental sensors and agricultural monitoring systems.

Furthermore, the MX4428 is equipped with comprehensive sensor integration capabilities. It can seamlessly interface with various sensors, making it a versatile choice for collecting a wide range of data types. From temperature and humidity sensors to motion detectors, the MX4428 can serve as a central hub for data gathering and transmission, providing real-time insights into environmental conditions.

Security is also a paramount consideration in the design of the MX4428. It incorporates robust encryption and authentication protocols to safeguard data integrity during transmission. This feature is crucial for applications involving sensitive information or those that require compliance with strict regulatory frameworks.

In summary, the Tyco MX4428 is a powerful and versatile device that boasts a combination of long-range communication, low power consumption, and comprehensive sensor integration capabilities. Its robust security features further enhance its appeal for critical applications across various industries. Whether for industrial, environmental, or smart city use cases, the MX4428 stands out as a reliable solution that meets the demands of modern wireless communication landscapes.