5
I
Calibration and Measurement
1.6 Press the
Enter
key, the meter begins the calibration.
Wait for the reading to stabilize, the display will shows
.
Single point calibration is completed.
Multipoint Calibration
Ensure that you have selected 2 or 3 points calibration in the setup
menu.
2.1 When the first calibration point is completed, the display will
show ---
/
. The meter prompts you to continue with second
point calibration.
2.2 Repeat steps 1.2 through 1.6 above until the meter shows
.
Calibration is completed.
•
Performing the conductivity calibration will simultaneously
calibrate the corresponding TDS value.
•
To exit the calibration without saving changes, press the
key.
Measurement
1. Press the
key to select the conductivity (
) or TDS (
)
mode.
2. Place the electrode into the sample. Wait for the measurement
to stabilize.
Communication
The BI-650 meter uses a standard Modbus-RTU protocol. All of the
data are character type (2 bytes). The response data ranges between
-32767 to 32767, hexadecimal.
PC Command
Definition
Length of Byte
Data
ID address
1
0 × 02
Command
1
0 × 03
Start address
2
0 × 0001
Data number
2
0 × 0002
CRC16
2
0 × 95F8
Meter Response
Definition
Length of Byte
Data
ID address
1
0 × 02
Command
1
0 × 03
Data Length
1
0 × 0002
Data
N
0 × 02 0 × BC
CRC16
2
0 × E4E8
•
If the response is 01 indicating the command is error.
•
If the response is 02 indicating the address is incorrect.
•
If the response is 03 indicating the byte length is incorrect.
Command 03: Read the data from the measurement
Command 04: Read the data from the setting
•
ID: 0 × 02 (Fixed)
•
03: Definition
Address:
0 × 0000 - Conductivity/
TDS reading
0 × 0001 - Decimal point
0 × 0002 - Measurement unit
0 × 0003 - Temperature (Reading × 0.1)
•
04: Definition
Address:
0 × 0000 - Read the low alarm limit
0 × 0001 - Position of decimal point for the low alarm limit
0 × 0002 - Measurement unit of the low alarm limit
0 × 0003 - Read the high alarm limit
0 × 0004 - Position of decimal point for the high alarm limit
0 × 0005 - Measurement unit of the high alarm limit
0 × 0006 - 4.00 mA correspond to conductivity value
0 × 0007 - Position of decimal point for above value (4.00 mA)
0 × 0008 - Measurement unit of above value (4.00 mA)
