FCC ID:
M5ZWOWPRES
Wireless Pressure Sensor Data Format
The Point Six, Inc. 418 MHz wireless sensors require a compatible receiver with the
ability to receive, error check and provide RS232 and RS422/485 interface. This
document describes the data format provided by the
HA9-wow
418 MHz. Receiver.
The transmit packet from a receiver is approximately 15 milliseconds in duration and
consists of 13 bytes of data:
1-byte ID/Mode field
8-byte serial number
2-byte pressure level as a 12-bit number
2-byte CRC-16 error check
The HA9-wow receiver processes this packet. The receiver performs a CRC-16 error
check on the packet. If the data is not accurate it is discarded. When a packet is received
that is error free it is converted to a 29-character packet and transmitted out the serial port
at 19,200 Baud. The data is transmitted serially in ASCII Hex format and terminated with
a CR character. This format requires two bytes for each byte of data; 14 data bytes x
2=28 plus the CR is 29 characters. See the HA8-wow specification for details.
The resulting binary data format of the packet is:
1-byte ID field
this field will contain a byte whose LSBit indicates the service
state of the transmitter, 0=normal, 1=service mode.
8-byte serial#
this field contains the serial number of the 1-Wire sensor.
2-byte data
this field contains the pressure data as a 12-bit number stored MSB
first. A value of 0FFF is a full scale reading and represents 30
PSIA. A zero input pressure will result in a reading of 0000.
2-byte CRC-16
this is the originally received data packet CRC as described above.
1-byte checksum
the checksum is a mod 256 sum of all the ASCII character values
in the response but does not include the CR
