Key Features

The 57 System MODBUS interface facilitates digital communication between the 57 System control system and an external computer system.

MODBUS is a widely supported digital data communication protocol that provides a standard set of commands that can be used for system data communication.

Two different interface modules support the most widely used electrical interface standards, ensuring compatibility with most external systems.

Using the MODBUS interface it is possible to read configuration, alarm status and other information from any channel in the rack and perform calibration and other procedures.

The MODBUS interface is typically used to connect a System 57 control system to a plant control system for centralised monitoring of system status, often with a graphical display.

The main features of the MODBUS interface are as follows.

Easy installation on engineering cards.

Compatible with the 5701. 5704 and 5704F control cards.

Simple field connection via DC input card terminal block for

Wiring up to 2.5mm² (14 AWG).

Operates as MODBUS RTU.

Supports MODBUS protocol functions 02. 03. 04. 06. and 16.

Provides sensor gas readings and alarm status for fault and prohibition,

Provides sensor gas readings and alarm status for A1. A2. A3. FIRE, STEL, LTEL, and rate alarms.

Sensor gas readings and alarm status for A1. A2. A3. FIRE, STEL, LTEL, and rate alarms.

Supports commands to inhibit, reset, zero, calibrate (span) and set alarm levels.

(range) and set alarm levels for all channels in the rack.

Supports RS485. RS422. and RS232 electrical standards.

Data signals are isolated from the system 57 power supply.

Asynchronous serial link with configurable baud rate, parity and stop bits.

Primary and secondary channel operation.

Half-duplex operation.

Multi-point transmission capability

Easily configured using engineering interface software.