L91B-1050/U Honeywell

The 5701 and 5704 control systems provide a complete solution for

the operational and engineering requirements of a multi-channel fire

and gas detection system. Each control card within the rack system

provides sensor drive, signal acquisition, gas concentration display

and comprehensive alarm facilities for one or more fire or gas sensors.

The MODBUS Interface facility extends the capability of the control

system by providing an external computer system with monitoring and

control functions for every gas sensor or fire detector connected to the

rack. The operation and alarm integrity of the System 57 is not

affected by the MODBUS Interface.

The digital data link uses a bi-directional 8-bit asynchronous serial

connection that is configurable for baud rate, parity and stop bits. Two

different modules are available, one supports both RS485 and RS422

electrical interface standards and the other supports the RS232

electrical interface standard. Depending upon the module type, system

configuration and the capability of the host computer, various

communication options are available as follows:

Interface Transmission Dual Highway Multi-drop

Mode Option Option

RS485 Half Duplex Yes Yes (31 Nodes)

RS422 Half Duplex No Yes (10 Nodes)

RS232 Half Duplex No No

The dual highway option provides a secondary or backup data link for

increased communication integrity. Multi-drop configurations allow a

single communication line to be shared by a number of devices

reducing the number of communication ports required at the host

computer.

RS232 provides the lowest cost solution for connecting a single

System 57 rack to a host computer.

RS485 provides the best solution for multi-drop connection of more

than one System 57 rack to a host computer and also gives the option

of a secondary highway.

RS422 is useful to provide multi-drop connection where the host

computer software does not have the facility for transceiver direction

control (transmit/receive/high impedance) that is required with RS485

connections.

We have the same series of models in stock. If you don't find the model you need, please contact us and we will provide you with an official quotation！