Danfoss m2 - System Overview; Alarms; Security Features; Battery Backup Functionality

4 Manual RS.8A.N5.02 © Danfoss 10-2007 m2 Version 3.11
System Overview
The m2 consists of a central monitoring unit which can monitor up to 16
local sensors or inputs which are usually located adjacent to the equipment
in question for example specic refrigerated areas (chiller cabinets, freezers,
cold rooms), plant rooms or gas detectors, up to 99 EKC - controllers and 32
standard RS485 connections (128 1/4 loads) via the third party bus. The precise
layout and conguration of these sensors and controllers is specic to each
installation, and it is not necessary for a typical operator to be familiar with the
operation of the sensors.
The m2 provides audio and visual alarms whenever an input exceeds its pre-set
alarm levels. For night operation, the system can be pre-set to dial-out using a
digital dialler or via a modem whenever an alarm occurs.
Security is provided by having passcode access to the protected settings. In the
case of mains failure, an alarm is triggered after a delay. The system can be pre-
set to dial-out to an external telephone number if required.
The m2 will always FAIL SAFE (except for modem dailout).
The unit is provided with battery backup to continue historical logging during
a power failure. In this case, the display backlight will switch o but the display
will keep running. When an alarm occurs, the alarm siren and the red ashing
backlight will still operate. The backlight will ash red, once every 5 seconds
until the alarm is muted.
Note: When a mains failure lasts longer than 1 hour, the unit will cease historical
logging and stop alarm checking. However, all existing historical readings
remain in memory and are not lost.
The m2 can monitor up to a maximum of 99 points, including up to 99 EKC -
controllers, and or an additional 32 standard RS485 connections (128 1/4 loads)
via the third party protocol.
If hard copy details of the monitor readings is required, a parallel printer port is
provided which can be connected to an Epson compatible parallel printer.
An RS232 serial interface via a 9-way ‘D’ type connector is provided which
allows either a directly connected IBM compatible Personal Computer (PC) or a
Minitel to be connected for operational and conguration purposes or to allow
connection to a modem.
If a PC is connected either directly or via the modem, the alarms and monitor
readings can be read and the set-up details can be changed remotely,
using Danfoss Central Station software (refer to manual RS.8C.G for more
information).
This manual will simply cover the conguration and use of the m2 in
monitoring and controlling a refrigeration installation.
Alarms
Security
Battery Backup
External Connections