Category: Honeywell

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.

Humidity

Humidity levels should be maintained between 40% and 60%, with a variation of less than 6% per hour.

If humidity levels are high, it may be necessary to condition the air inside the cabinet and monitor humidity.

During maintenance, look for signs of condensation inside the cabinet, which is a sign that the climate control is beginning to fail.

Corrosion

Look for visible signs of corrosion on paint and bare metal surfaces inside the cabinet.

Keep cabinet doors closed to prevent corrosive salts and chemicals from entering the cabinet. Watch for metal fragments, such as zinc in the air.

Watch for metal debris such as airborne zinc from the underside of raised floor tiles commonly used in computer rooms or from any nearby hardware assembly or construction activities.

If deterioration occurs that you can see, then even further damage can occur in components you can’t see, so steps should be taken to further minimise contaminants.

Dust

Check the surface of the PSU and the bottom of the cabinet for dust, if you find a high concentration of dust, remove the dust using a soft anti-static brush and vacuum inside the cabinet.

Replace the cabinet fan dust filter periodically. The specific www.cniacs.com filter varies depending on the cabinet installed.

Cabinet Fans and Seals

Ensure that the cabinet fans are working properly, filters are clean and free of obstructions, protective plates and covers are secure, and all cabinet penetrations are sealed.

This is critical to avoid premature PSU failure.

New fan assemblies can be ordered with Honeywell part number FC-FANWR-24R.

Honeywell recommends replacing the fan every 8 years of operation.

Replace Power Supplies Before Failure

Improve System Reliability

Even with proper maintenance and environment, power supplies should be replaced before they fail.

For redundant systems, a phased approach may be helpful, where one power supply in each pair is replaced early and then the other is replaced at the next maintenance cycle.

Reliability can vary greatly depending on the load and temperature of the power supply.

Normal temperatures are kept at 35 degrees Celsius and a fully loaded PSU may have a shorter life depending on the temperature, reflecting the importance of keeping the fans running.

Many security systems use redundant power supplies so that each unit can carry 50% of the load during normal operation.

It is also common to specify spare capacity for PSU loads.

For example, with at least 25% spare capacity, each PSU can only carry 40% of the load in a worst-case scenario.

In this configuration, temperature and load do not limit PSU reliability.

Other factors, such as dust and humidity, are limiting, although these environmental conditions vary widely, making the exact life expectancy unknown.

Humidity

Humidity levels should be maintained between 40% and 60%, with a variation of less than 6% per hour.

If humidity levels are high, it may be necessary to condition the air inside the cabinet and monitor humidity.

During maintenance, look for signs of condensation inside the cabinet, which is a sign that the climate control is beginning to fail.

Corrosion

Look for visible signs of corrosion on paint and bare metal surfaces inside the cabinet.

Keep cabinet doors closed to prevent corrosive salts and chemicals from entering the cabinet. Watch for metal fragments, such as zinc in the air.

Watch for metal debris such as airborne zinc from the underside of raised floor tiles commonly used in computer rooms or from any nearby hardware assembly or construction activities.

If deterioration occurs that you can see, then even further damage can occur in components you can’t see, so steps should be taken to further minimise contaminants.

Dust

Check the surface of the PSU and the bottom of the cabinet for dust, if you find a high concentration of dust, remove the dust using a soft anti-static brush and vacuum inside the cabinet.

Replace the cabinet fan dust filter periodically. The specific filter varies depending on the cabinet installed.

Cabinet Fans and Seals

Ensure that the cabinet fans are working properly, filters are clean and free of obstructions, protective plates and covers are secure, and all cabinet penetrations are sealed.

This is critical to avoid premature PSU failure.

New fan assemblies can be ordered with Honeywell part number FC-FANWR-24R.

Honeywell recommends replacing the fan every 8 years of operation.

Replace Power Supplies Before Failure

Improve System Reliability

Even with proper maintenance and environment, power supplies should be replaced before they fail.

For redundant systems, a phased approach may be helpful, where one power supply in each pair is replaced early and then the other is replaced at the next maintenance cycle.

Reliability can vary greatly depending on the load and temperature of the power supply.

Normal temperatures are kept at 35 degrees Celsius and a fully loaded PSU may have a shorter life depending on the temperature, reflecting the importance of keeping the fans running.

Many security systems use redundant power supplies so that each unit can carry 50% of the load during normal operation.

It is also common to specify spare capacity for PSU loads.

OVERVIEW

The Honeywell FC-SCNT01 is a safety controller module designed for industrial process safety applications.

It acts as the brain of the Safety Instrumented System (SIS), performing critical Safety Instrumented Functions (SIFs) to maintain safe operations.

Functional Features

Dual-channel architecture: Ensures redundancy and fault tolerance for reliable safe operation.

SIL 3 certification: Highest level of safety integrity for critical applications.

Eight channels: Flexibility to monitor a wide range of process parameters.

24VDC input voltage: Compatible with standard industrial power supplies.

400mA output current: To drive safety-related actuators and devices.

Technical Specifications

Number of channels 16 (8 inputs, 8 outputs)

Rated Voltage: 24VDC

Refer to data sheet for current ratings.

Safety ratings Conforms to relevant safety standards (ATEX, IECEx)

Operating Temperature Typically -40°C to +70°C

Main Functions:

Input Functions: The FC-SCNT01 module is capable of receiving input signals from field devices, such as fire alarm signals from smoke detectors, door and window opening and closing status, etc. The input signals are processed and then processed by the FC-SCNT01 module.

These input signals are processed and sent to the main controller of the security system.