Honeywell System 57 MODBUS Interface Module

Master: A master device is a node that controls the transmission of data in a communication system by sending requests to slave devices.

Slave Device: A slave device transmits data to the communication line only in response to a request from the master device.

Structure

The System 57 MODBUS interface can be pre-installed in a new system or retrofitted to an existing system as a kit.

Two kits are available, one supporting RS485 and RS422 electrical standards and the other supporting RS232 electrical standards.

Each kit includes

a. A small PCB MODBUS interface module that plugs into the J1 and J2 interfaces of the Engineering Card.

b. Two integrated circuits that plug into the expansion sockets provided on the project card.

The serial data interface is connected via the six-way expansion terminal block TB2 on the DC input card.

In order to provide MODBUS interface functionality, the enhanced Project Card software must be installed.

The new software is fully compatible with the original Project Card software and is supplied with the kit as plug-in integrated circuits.