1User manualALFA(NET) 51Rail-Thermostat.VDH doc. 032797 Version: v1.2 Date: 20-02-2007Software: ALFANET51 File: Do032797.WP8 Range: -50/+50,0C* Installation.On the connection diagram of the ALFA(NET) 51 is shown how the sensors, power supply and relays areto be connected. After connecting the ALFA(NET) 51 to the power supply, a self test function is started.As this test is finished, the measured temperature appears in the display. Normally this is the temperatureof sensor-1, unless sensor-2 is active as control sensor (P05=1) in that case the average temperature ofboth sensors is displayed and used for control. The ALFANET 51 is by use of the ALFANET PC-INTERFACE controllable on the PC.* Control.The ALFA(NET) 51 thermostat can be controlled by four pushbuttons on the front. These keys are:SET - view / change the setpoint.UP - increase the setpoint.DOWN - decrease the setpoint.MODE - relay status key.* Viewing setpoint.By pushing the SET key the setpoint appears in the display. The decimal point of the last display startsblinking. A few seconds after releasing the SET key the setpoint disappears and the measuredtemperature is shown again in the display.* Changing setpoint.Push the SET key and the setpoint appears in the display. Release the SET key. Now push the SET keyagain together with the UP or DOWN keys to change the setpoint. A few seconds after releasing the keysthe measured temperature shows again in the display.* Viewing the individual sensors.By pressing the UP and DOWN key together, the individual sensors can be shown in the display. Afterreleasing the keys, the measured temperature of sensor-1 can be shown by pushing the UP key or themeasured temperature of sensor-2 can be shown by pushing the DOWN key. A few seconds afterreleasing the keys the (average) temperature shows again in the display.* Status of the Relays.By pushing the MODE key the display shows the status of the relays. Each display segment shows thestatus of the relay output, showing 0=off and 1=on. The code 110 means relay 1 and 2 are on and relay 3is off.