Festo CPX-2AA-U-I, Электронное руководство

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2. Analogue input module CPX−2AE−U−I
2−28
Festo P.BE−CPX−AX−EN en 0503b
2.4.5 Channel−specific module parameters Limits
You can determine limits with the channel−specific para
meters Lower limit" and Upper limit". The meaning of the
limit parameters depends on the parametrized data format of
the module.
With data format VZ + 15 bits linear scaled", the limits have
the function of defining the scaling end values of the data
range. This results in an additional scaling of the analogue
values.
If the input data lie outside this data range, a diagnostic
message can be generated with appropriate parametrizing.
With other data formats the data range is already defined by
the scaling end values. In this case, the limits permit data
monitoring even within the data range.
D ata for mat
1)
D ata r an g e L imits / sca l in g en d v a l ues
2)
VZ + 15 bits
linear scaled −30000... +30000 Lower scaling end value:
−30000... +29999 Upper scaling end value:
−29999... +30000
VZ + 12 bits
right−justified 0...4095 Lower limit:
0...4094 Upper limit:
1...4095
VZ + 15 bits
left−justified 0...32760 Lower limit:
0...32759 Upper limit:
1...32760
VZ + 12 bits left−
justified + diagnosis
3)
0...32760 Lower limit:
0...32752 Upper limit:
1...32760
1)
VZ = Sign
As the analogue inputs with the Fixed value" data formats VZ + 12 bits right−justified",
VZ + 15 bits left−justified" and VZ + 12 bits left−justified + diagnosis" generate only positive
signals, the sign bit with these formats is always 0.
2)
The lower limit/scaling end value must always be less than the upper limit/scaling end value.
3)
If the max. voltage or current values are exceeded, values greater than 4095 will also be output.
Tab.2/19: Limits or scaling end values of the analogue input modules