Sierra Monitor Corporation Modbus Communications Interface User Manual

Modbus Communications Interface

The Sentry Controller Modbus RTU Communications Interface enables Sentry to easily communicate with PC based Distributed Control Systems and graphic based human-machine interfaces and via the FieldServer T echnologies gateway to a wide range of other protocols.

The Sentry system from Sierra Monitor offers comprehensive, cost effective solutions to many specific gas management requirements. From a simple 4-point monitoring system to a complete plant wide hazardous gas monitoring system with hundreds of gas detection points, Sentry meets the need.

With the Modbus communications interface Sentry can easily interface with a PC-based Distributed Control System to provide a graphical display of hazardous gas conditions in the plant. PC-based DCS software in conjunction with Sentry provides the operator enhanced data acquisition, alarming and alarm management, historical trending, distributed architecture, and integration into the plant’s distributed control system.

Sentry’s Modbus communication interface provides over 620 different parameters accessible by the PC-based DCS software, including:

• gas concentration

• alarm setpoints

• sensor diagnostic messages

• historical reset time/date

• power up/down time/date

• trouble alarm time/date

• minimum/maximum values plus time/date

• high/low alarm latch/non-latched

• auto calibration enabled

• calibration status/coefficients

• calibration concentrations

• calibration due date

• zone option enabled

• operate mode

Sentry

Using the optional FieldServer T echnologies Gateway the user can convert from the Modbus RTU output to a wide variety of other protocols including DF1, DH+, Profibus, Modbus TCP, ControlLogix and many more.

FieldServer T echnologies is a division of Sierra Monitor Corporation. More information on FieldServer products can be found at www.fieldserver .com

Ordering Information

5387-50Modbus Communications Interface 4301-10Converter RS-232/RS-485, 9VDC

Sierra Monitor Corp. 1991 T arob Ct., Milpitas, CA 95035, USA, 408-262-6611, 800-727-4377, F AX: 408-262-9042

Web Site: http://www.sierramonitor.com E-Mail: sales@sierramonitor.com