27
“DER query”
frame format –the data display system to the detecting unit
D7 D6 D5 D4 D3 D2 D1 D0
0
1
0
1
0
1
0
1 Byte 55h
–
start-of-frame character
Byte AAh
1
0
1
0
1
0
1
0
0
0
0
0
А3
А2
А1
А0
D7...D4
–
“D
E
R query”
frame code
D3...D0
–
detecting unit address *
* -
0Fh
address – broadcast
address. All detecting units respond to the query with such address.
“Current DER”
frame format –the detecting unit to the data display system
D7 D6 D5 D4 D3 D2 D1 D0
0
1
0
1
0
1
0
1 Byte 55h - start-of-frame character
Byte AAh
1
0
1
0
1
0
1
0
0
0
0
1
А3
А2
А1
А0
D7...D4 -
“Current D
E
R”
frame code
D3...D0 - detecting unit address
DER0 (low byte)
DER,
fixed point number,
Least significant bit (LSB) = 0.01
µSv/h
DER1
DER2
DER3 (high byte)
Byte
Statistical error of measurement
D7
0
0
0
0
D2 D1 D0
D0,D1
–
self-testing results of the
detecting unit
D0=1
–
failure of the high sensitivity
detector
D1=1
–
failure of the low sensitivity
detector
Reliable measurement result character
D2=0
–
result is reliable
D2=1
–
result is not reliable *
D7=0
–
LSB DER = 0,01
µSv/h
D7=1
–
LSB DER = 0,1
µSv/h
control
arithmetical checksum with a carry
* - measurement result is accepted as not reliable if the statistical error of measurement exceeds the maximum permissible
error of the measurement