ADOS GmbH
MWS 897
Page 1
1.
Introduction
The ADOS gas warning unit is a microcontroller-aided multi-channel gas monitoring unit with warning
and control functions.
Various types of sensor can be connected via a 4-20mA current interface, using 2 or 3 wire
technique.
All information significant to operation, is displayed in clear on a 2-line and 16-digit display. The
information includes the actual gas value, measuring point, alarm status or fault.
The alarms and centralised malfunctions are indicated on LED´s. Three floating alarm outputs can be
used optionally for ventilation and alarm control. One relay is responsible for fault indication.
Two keys are used for operating the equipment. These keys, together with menu-assistance, are
used for setting minimal and maximum limit values, the measuring points, as well as other significant
parameters, without any previous knowledge of programming skills. Alarms can be cancelled by
keystroke. The alarm outputs can be tested without any application of gas.
The unit incorporates a RS232 interface for data communications and a voltage output of 0-5V.
The ADOS gas warning unit MWS 897, depending on the model, can be operated on 230 V~, 110 V~
or 24 V= voltage supplies.
The unit is enclosed in a plastic wall mounting housing, protection class IP 54.
2.
Operating Summary
Display and operating controls are located on the frontside of the unit. Two buttons are used for the
basic settings of the unit, stopping the measurement cycle, resetting the alarms and for performing
test routines.
The basic settings of the unit are menu assisted, via the LC-Display and the following keys.
“SELECT”
* switching between cyclic and stopping measure mode
* selecting a menu item
* change a value in a menu sub-item
“ENTER”
* for selecting a menu item
* to quit an alarm
By simultaneously pressing “ENTER” and “SELECT” keys, entry is made for the input of the code.
After having entered the right code (number of the unit type “897"), entry is allowed into the basic
adjustments. Here, all settings can be checked and modified if required.
A return back to the normal measurement cycle is made pushing the “SELECT” key or automatically
after 90 seconds, if no new key is pressed.
By pushing the “ALARM RESET / ENTER” key during measurement, the internal buzzer can be
prematurely cleared. The alarm (LED & relay outputs) can only be cancelled if the alarm condition is
no longer present. Therefore it is not possible, if the actual gas value > limit.