Distance sensor

Hi,

I tested to get a sampling data from Watchport/D sensor using XBee sensor adapter.
My XBee adapter firmware is ZNet2.5.

Connections :
PC(serial analyze soft) ---- XBee RS232C adapter ---- XBee sensor adapter ---- Watchport/D sensor

  1. Transmit 1S command from serial analyze software to XBee sensor adapter. API Identify is 0x17.

  2. Receive a sampling data from XBee sensor adapter to serial analyze software. API identifier is 0x97.

  3. Compute Distance using test program that I attached. I programed refering python sample program(xbee_sensor.py).

I could not get correct distance value.
For example, distance value is 20 cm even if an object is within 1 meter from distance sensor.

This is sampling data from distance sensor. An object is within 1 meter from distance sensor.

7E 00 1A 97 6E 00 13 A2 00 40 0A 39 42 76 17 31 53 00 01 00 00 00 C0 00 0E 00 C0 FF FF E2

(Sensor adapter is : 0013A200400A3942)

Please let me know how to solve this issue.