Sigfox WSSFCB-NH3, Руководство пользователя

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From the existing A and B values and the measured value Y_o and Y_s and the 0ppm (zero standards) and 25ppm (for
example using 25ppm NH3 standard gas), you can calculate the new value of A and B as below formula.
Ex: We have values
Two calibration points Standard value The value read from Sigfox device
1 50 70
2 1000 1100
The old A configuration 1
The old B configuration 0
We have:
A = (1000-50) / (1100-70) = 0.92233
From the formula: Y = AX + B. Then B = Y - AX = 1000 - 0.92233 x 1100 = -14.56311
The new A configuration 0.92233
The new B configuration -14.56311
As the A and B values are separated values in the memmap of the sensor, we need to use 02 downlink messages to
send to the sensor. Each message will send 1 value of A or B.
For example: A = 1.1 and B = 0.2. Here are the downlink message for setting A & B
Parameter PRM_ADDRESS PRM_LENGTH PRM_VALUE DOWNLINK_TYPE Full Downlink
(bytes) 1 1 4 2 8
CONSTANT_A 0x16 0x04 = 4 0x3F8CCCCD = 1.1 0x0005 16043F8CCCCD0005
CONSTANT_B 0x18 0x04 = 4 0x3E4CCCCD = 0.2 0x0005 18043E4CCCCD0005
HIGH_CUT 0x1A 0x04 = 4 0x447A0000 = 1000 0x0005 1A04447A00000005
LOW_CUT 0x1C 0x04 = 4 0x00000000 = 0 0x0005 1C04000000000005
SENSOR_BOOT_TIME 0x1E 0x04 = 4 0x000000C8 = 200 0x0005 1E04000000C80005
SYSTEM_SENSITIVITY 0x32 0x04 = 4 0x41300000 = 11 0x0005 3204413000000005
- Carefully remove the filter;
- Remove the exiting sensor module by using your finger to grip and pull it out;
- Unbox the new sensor in the box;
10.3 Calculate the new value A and B
10.4 Set the new value A and B by Downlink
11. Sensor module replacement:
11.1 Remove old sensor module:
11.2 Install new sensor module: