Specifications

Ammonia Gas Monitor – Multi Zone
Instruction 3015-5113 47
Appendix B
RS-485 Communication Protocol
Overview
The following instructions are intended as a guide for integrating the AGM-MZ network into a Building
Management System. If you are unfamiliar with complex systems of this type, it is recommended that you
contact Bacharach for technical assistance.
MODBUS RTU Protocol
The AGM-MZ monitor communicates with master devices (such as the AGM-RD or a Building Management
System) over the RS-485 serial interface. Because the monitor is configured with a two wire RS-485 serial
bus, data transmission occurs in ‘half-duplex” mode. Therefore, only one device may be in transmit mode at
any given time.
Programmers should refer to the “MODBUS Protocol Reference Guide” for details and more comprehensive
instructions. The guide is available on the Modicon web site at:
http://www.modicon.com/techpubs/TechPubNew/PI_MBUS_300.pdf
Specific communication software is available at: http://www.bacharach-inc.com/downloads.htm