EATON MTL831C Analog Converter

Description

EATON MTL831C Analog Converter

EATON MTL831C Analog Converter

The MTL831C Analog Transmitter can transfer a number of hazardous area input signals to the safe area down a data highway consisting of a single shielded, twistedpair cable. It is intrinsically safe and can therefore be mounted in Zone 0 hazardous areas or hazardous locations. The MTL831C can monitor up to 16 inputs from THC or millivolt sources or 2, 3 or 4-wire RTDs or potentiometers.

A data highway is provided that can carry both signal and power over distances up to 2km, depending on the application, the cable and the (noise) environment. Shielded twisted pair is highly recommended. At the other end of the data highway, an MTL838C Receiver translates the information transmitted from the MTL831C. One or two MTL831Cs may be connected to a single MTL838C. The MTL838C provides a *Modbus® serial data output representation of the inputs together with status information. When the MTL831C transmitter is mounted in the hazardous area, the data highway must be protected by an MTL5553/MTL5053 Isolator/Power Supply mounted in the safe area.

Installation of the MTL831C multiplexer transmitter is divided into three main topics.

• Mechanical Installation – how to mount the MTL831C and how it may be fitted into an enclosure.

• Electrical Connections – the sensor and highway connections. If units are installed in our enclosures, it details any special wiring arrangements.

• Configuration – the address is configured with a user supplied jumper wire. The remaining configuration is either over a Modbus® link or software on a PC.

The on-site instrument of the process station I/O unit transmits 4-20mA or 0-10V analog signals, and the on-site executing mechanism also receives such analog signals. The process station can recognize and process binary digital signals, so the input and output of signals from instruments and electrical equipment need corresponding I/O units to achieve. The main function of the I/O unit is to convert the input electrical signals of the field instrument or motor into digital values that can be recognized by the process station. At the same time, the digital values processed by the process station are converted into corresponding electrical signals and output to the on-site actuator and motor. The I/O unit must have sufficient stable electrical and mechanical performance to be capable of working normally under various conditions, such as strong electromagnetic interference, severe water vapor and dust, high-frequency vibration, surges, and so on. The I/O unit must also be able to achieve flexible layout and can be arranged anywhere as needed.
The I/O unit in a highly reliable DCS system must also have fault self-diagnosis function, wide electric hot swapping, redundancy and other functions. The operator station and engineer station are PV machines used for operation, monitoring, alarm, trend display, recording, and printing reports. The operator station is usually equipped with operating software to complete the above functions, and is connected to the process control station through a communication network.
The engineer station is a computer used for configuring process control software, diagnosing and monitoring the operation of process control stations, and for QCS engineers to develop, test, and maintain DCS systems. According to the size of the system, the operator station is required to be flexibly arranged. In small-scale applications, the operator station is usually used as an engineer station.
The communication network DCS generally adopts a two-layer communication network structure: process level and operation level. Process level communication network: The on-site I/O modules, especially the sampling data of analog quantities (machine code, 213/scan cycle), are very large, and there are many on-site interference factors. Therefore, a network communication standard with high data throughput and strong anti-interference ability should be adopted, which is generally also known as the field bus communication standard. The fieldbus hardware is based on widely supported communication methods on industrial devices such as R485, which meets the requirements of on-site communication. Operation level communication network: The sampling data of I/O is converted by the CPU into shaped or real data, which is transmitted on the operation level network. Therefore, operational level networks can adopt network standards with moderate data throughput, fast transmission speed, and convenient connection. Meanwhile, due to the fact that the operation level network is generally arranged in the control room, the requirements for anti-interference are relatively low. Ethernet, which supports the TCP/IP protocol standard, is a commonly used operational level communication network. The operational level communication network used by the Haitian DCS system is industrial Ethernet. There are various media available, including optical fiber, thick cable, and twisted pair. The process level communication network is the PROFIBUSDP network.