User`s guide

MASSA PRODUCTS CORPORATION

Product Manual- April 24, 2012 25 M3 Wireless Ultrasonic Level Sensor

APPENDIX E

Outgoing Auto-Message Message Format

This is the automated outgoing message format when the sensor wakes up from Deep Sleep. The auto_message_length

setting will be the same number indicated in the “EventsToRetrieve” byte. This setting allows you to reduce the size of

this message by reducing the amount of records for such reasons as limiting the size for cell plan costs.

Host ID Sensor ID total # of bytes 1 Record Pointer # of event blocks oldest record newest record checksum

default=251 default=1 of this message 1 to 111 1 to 8 (8 bytes) (8 bytes)

Event Record (n) block defined (8 bytes):

<EventLSB><EventMSB>: 2-byte Event Counter will automatically increment for each new data acquisition

<Status1>: This status byte is parsed as;

<bit7> Sensor Error; 0=OK, 1=Fault (read Configuration Register 65)

<bit6> <bit5> undefined, factory only

<bit4> Ultrasonic Gain Control (short); 0=Low, 1=Hi

<bit3><bit2> Radio Signal Strength (of Last Reception); 00=weak, 01=moderate, 10=strong, 11=very strong

<bit1><bit0> Ultrasonic Signal Target Strength; 00=<25%, 01=50%, 10=75%, 11=100%

<Status2>: This status byte is parsed as;

<bit7><bit6><bit5> Ultrasonic Sensitivity Settings; 000=Very Low, 001=Low, 010=Normal(default),

011=Normal-Hi, 100=Hi, 101=Very Hi, 110=Custom

<bit4><bit3> Ultrasonic Gain Control (long); 0=Low, 1=Hi, 2=TimeVarying

<bit2> Temperature Probe; 0=Internal (default), 1=User Programmed value)

<bit1> Min Distance Processing; 0=Disabled, 1=Enabled (default)

<bit0> Range Bytes Resolution; 0= ÷128 (models M3/150 & M3/95), 1= ÷64 (model M3/50)

<RangeLSB><RangeMSB>:

Ultrasonic Range (in inches). Resolution for model M3/150 and M3/95: RangeMSB:RangeLSB ÷ 128.

Model M3/50: RangeMSB:RangeLSB ÷ 64. Status2 <bit 0> indicates resolution. No target detected (no

echo) is indicated with RangeMSB:RangeLSB=0. RangeMSB = 255 indicates range not acquired (not

available in data history buffer).

Temperature (ºC) = 0.587085 * <TemperatureReading> - 50

Battery Voltage (volts) = ( <BatteryReading> - 14 ) / 40

* Reminder: Resolution of the RangeLSB and RangeMSB is defined by Status2 bit 0.