Events

Here the events sent by the module is described.

The data coding byte is the measurement data coding format described in the VSCP specification.

The normalized integer is stored as a two complement 16-bit integer. To convert

1. Calculate the 16-bit twos complement as MSB byte * 256 + LSB byte.

2. If the most significant bit is not set (Equal or less then 32767) this is a positive temperature. Divide by 100 and you have the temperature.

3. If the most significant bit is set (Greater than 32767) this is a negative temperature. Now invert the result (the bits are inverted; 0 becomes 1, and 1 becomes 0) and add one to the result. Dive by 100 and you have the temperature.

The data part of the event will be

1. Byte 0: Normalized integer, Celsius, Sensor 1
2. Byte 1: Decimal point should be shifted two steps to the left.
3. Byte 2/3: Bit 16 is a one meaning it's a negative number. Temperature is a two complement number. 0xF060 = 0b1111000001100000. Invert which give 0b0000111110011111 add one which give 0b0000111110100000 = 4000. Divide by 100 gives 40.00 The read temperature is -40.00 ºC.

The data part of the event will be

1. Byte 0: Normalized integer, Celsius, Sensor 1
2. Byte 1: Decimal point should be shifted two steps to the left.
3. Byte 2/3: Bit 16 is zero meaning it's a positive number. 0x2EE0 = 12000. Divide by 100 gives 120.00. The temperature is 120.00 ºC.

The data part of the event will be

1. Byte 0: Normalized integer, Fahrenheit, Sensor 5
2. Byte 1: Decimal point should be shifted two steps to the left.
3. Byte 2/3: Bit 16 is a one meaning it's a negative number. Temperature is a two complement number. 0xFF76 = 0b1111111101110110. Invert which give 0b0000000010001001 add one which give 0b0000000010001010 = 138. Divide by 100 gives 1.38 The read temperature is -1.38 ºF.

To help to interpret data the three tables below list the datacoding bytes for Kelvin, Celsius and Fahrenheit temperature presentation.

If enabled the event is sent when a temperature sensor goes below a low alarm set point (see Low-alarm-registers) or above a high alarm set point (see High-alarm-registers). The hysteresis registers is used so that after an alarm event has been sent a new alarm event is not sent until the temperature goes below/above the value set in the set point plus(low)/minus(high) signed content of hysteresis register.

A read of the alarm register will reset the alarm status and alarm events will not be sent out again until the the temperature changed with the hysteresis amount.

Zone and sub-zone are the modules settings for the sensor generating the alarm. See register 74-85

If enabled, the event CLASS1.CONTROL, Type=5, TurnOn or CLASS1.CONTROL, Type=6, TurnOff (Bit 5 in control register must be set (see Control-registers])) is sent when the temperature goes below or above the low(see Low-alarm-registers/high(see High-alarm-registers alarm set points. Settings in the control register bit 6 (see [sub:Control-registers]) decides which of the TurnOn/TurnOff event that is sent. The hysteresis setting (see [sub:Sensor-hysteresis-registers]) tells how much a temperature must raise or fall below the alarm set point before a new event will be sent.

Index is 0 for Sensor 0, 1 for Sensor 1, 2 for Sensor 2. 3 for Sensor 3. 4 for Sensor 4. 5 for Sensor 5.

Zone information is fetched from sensor zone register (see sensor zone information registers).

Sub zone information is fetched from sensor sub-zone register (see sensor zone information registers).

If a SYNC event is received by the module it will check the zone/subzone parameters of the event and send out temperature measurement event(s) for all sensors that match. This can be a handy feature to use of one want synchronized data from several sources.