B&K Precision 889B - Manual - Manual (Page 20)

19
1101
1110
1111 Auto-Ranging Auto-Ranging
Bit 17
0 Short Cal Short Cal
1 Open Cal Reserved
Bit 21 – Bit 18 Measurement Modes
0000 Reserved
0001 LCR
0010 DCV
0011 ACV
0100 Diode
0101 Continuity
0110 DCA
0111 ACA
Others Reserved
Bit 23 – Bit 22 Reserved
00
01
10
11
For example: if LCR function, Cp with D measurement mode is selected in Auto-ranging with Relative and
Open/Short Calibration are turned off and test signal is 1 Vrms in 1 KHz, then the command is as following:
MOD 000001111110001011010010
2. The results of the measurement that will be sent from the 889B to a remote PC will be packed in either
7-byte or 11-byte format.
When dual data (such as Cp with D) will be sent, the data is packed in 11-byte format shown as following:
Lead_code1 : 02
Lead_code2 : 09
Data_code : 8-byte long; two 32-bit floating point number format; the first 4-byte is the main reading (Cp)
and the second 4-byte is the secondary reading (D)
Checksum : -((02+09+data_code) && 0x00FF)
02 09 M-B0 M-B1 M-B2 M-B3 S-B0 S-B1 S-B2 S-B3 CS
where M-Bx and S-Bx are the four bytes floating point format of main and secondary reading which is sent
from the lowest byte first.
When only main reading (such as DCR) will be sent, the data is packed in 7-byte format described below:
Lead_code1 : 02
Lead_code2 : 03
Data_code : 4 bytes long; the 32-bit floating point format of the main reading
Checksum : -((02+03+data_code) && 0x00FF)
02 03 M-B0 M-B1 M-B2 M-B3 CS
When only secondary reading (such as DCV) will be sent, the data is packed in 11-byte format described
below:
Lead_code1 : 02
Lead_code2 : 09