Burkert Type 8644 - Manual (Page 111)

8644/phoenix - 107
S
YSTEM
D
ESCRIPTION
Se-
rial
no. Setting Write Read Con-
trol
byte
Data byte Explanation
1 Unit of pressure
display on
pressure
module
1
X 0x91 (0) to (2)
[0x00:0x02] Unit Displayed in bar, kPa or psi
0x00 (0) = bar, 0x01 (1) = kPa, 0x02 (2) = psi
X 0x81 dc The unit set in the module is read out.
Return value of data byte: 0x00 = bar, 0x01 = kPa, 0x02 = psi
2 Lower threshold
value²
X 0x92 (-10) to (99)
[0xF6:0x63] Range of values: -10 to 99 (-1 to 9.9 bar)
The lower threshold value must be smaller than the upper threshold
value.
X 0x82 dc The lower threshold value set in the module is read out.
Return value of data byte: -10 to 99 (-1 to 9.9 bar)
3 Upper threshold
value²
X 0x93 (-9) to (100)
[0xF7:0x64] Range of values: -9 to 100 (-0.9 to 10 bar)
The upper threshold value must be greater than the lower threshold
value.
X 0x83 dc The upper threshold value set in the module is read out.
Return value of data byte: -9 to 100 (-0.9 to 10 bar)
4 Reaction time² X 0x94 (0) to (255)
[0x00:0xFF] Range of values
Value = 0 threshold treatment deactivated
Value = 1... 255 threshold treatment activated
Reaction time that may be set: 0 ms to 7.62 s (in 30 ms steps)
Calculation reaction time = (value-1) x 30 ms
X 0x84 dc Feedback value data byte 0 ... 255 - set threshold value (see
above)
5 Sensitivity²
(degree of
smoothing) X 0x9F (1) to (100)
[0x01:0x64] Range of values: 1 to 100
The larger the value, the more strongly the pressure value last
measured is included in the mean value calculation (PT-1-filter), the
higher is the sensitivity and the lower is the degree of smoothing.
Value 100, i.e. the pressure value measured is weighted to 100 %
and the previous measurement to 0 %. In this case the filter is
deactivated.
The sampling frequency of the pressure measurement module is 50
Hz (TA = 20 ms).
X 0x8F dc Return value of data byte: 1 to 100
6 Acknowledge 0xAA dc Acknowledge telegram is required between different
parametrizations. Instead of this, one can request process data.
1 see Unit of pressure display
² see Threshold values and reaction time
dc: don't care
( ) decimal values in brackets
Unit of pressure display
The pressure value is always sent over the bus in kPa. The pressure unit can only be canged on the local
unit.
Setting the control and data bytes (overview)
Value sensitivity
≈ ≈ 1
degree of smoothing