Fluke PM3082 Service Manual page 484

CORRECTIVE MAINTENANCE PROCEDURES
The configuration of group 0 and 1 is shown in the table:
Group
0
1
The data representation for group 0 is '0:ABCD\ Each character represents the hexadecimal (16
possible states) information for 4 outputs (total 16 outputs):
- Character 'A' represents the information for D9004 outputs 14, 13, 12, 11.
- Character 'B' represents the information for D9004 outputs 4, 5, 6, 7.
- Character 'C' represents the information for D9003 outputs 14, 13,12, 11.
- Character 'D' represents the information for D9003 outputs 4, 5, 6, 7.
The data representation for group 1 is '1 :ABCD 1 :EFGH'. Each character represents the hexadecimal
(16 possible states) information for 4 outputs (total 32 outputs):
- Character 'A' represents the information for D9012 outputs 14,13,12, 11.
- Character 'B' represents the information for D9012 outputs 4, 5, 6, 7.
- Character 'C' represents the information for D9007 outputs 14, 13,12,11.
- Character 'D' represents the information for D9007 outputs 4, 5, 6, 7.
- Character 'E' represents the information for D9008 outputs 14, 13, 12, 11.
- Character 'F' represents the information for D9008 outputs 4, 5, 6, 7.
- Character 'G' represents the information for D9011 outputs 14, 13, 12, 11.
- Character 'H' represents the information for D9011 outputs 4, 5, 6, 7.
Note: the data for D9013 is not displayed. This buffer is only used when turning-on the oscilloscope:
it tests if hardware and software belong to each other.
8.12.4.6 Repair tools / cbus
To control on/off functions in the CH1 ... CH4 attenuators and in the main and delayed time base,
there are 3 buffers on unit A1 of the instrument. This configuration is called the 'c-bus'. Each buffer
has 13 outputs and can be regarded as a shift register of 13 bits. Each buffer has its own enable
signal. The test makes the data (SDA) visible that is shifted by the microprocessor into the buffer.
Synchronization is achieved via SCL.
The configuration is shown in the table:
Enable signal
DLENO-HT
DLEN1-HT
DLEN2-HT
The data representation for D9006 is '0:ABCD'. Each character represents the hexadecimal (16
possible states) information for 4 outputs. The data representation for D9001 and D9002 is more
complex: these buffers drive the pulse relays in the CH1 ... CH4 attenuators. Changing an attenuator
setting can cause the generation of several '0:ABCD' blocks of data. Refer to chapter 5.1.1 for
information on how the pulse relays are controlled. D9001 controls CH1 and CH2: data blocks have
the configuration '0:ABCD'. D9002 controls CH3 and CH4: data blocks have the configuration
'1 :ABCD'.
Enable signal
STROBEO-HT
STROBE1-HT
Buffer Name of circuit diagram
D9001 Control circuits
D9002
Control circuits
D9006 Main time base
Buffers
Name of circuit diagram
D9003
Control circuits
D9004 Control circuits
D9011 MTB trigger
D9008 Time base logic
D9007 Delayed time base
D9012 DTB trigger
D9013
DTB trigger
8 - 1 7