Festo CPX-P-8DE-N Series, Description

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3. Input module CPX-P-8DE-N-...
3-14
Festo P.BE-CPX-P-EA-EN en 1209NH English
Inputs 4 ... 7 can be used exclusively as digital inputs. Inputs
0 ... 3 also support the counter and frequency measurement
operating modes, whereby only input 0 supports the fre-
quency measurement up to 10 kHz (
operating mode D
in Tab. 3/8).
Configuration of process image inputs (PII)
Byte 0 in PII For inputs that are configured as a digital input, the signal
states (0/1) of the digitised input signals are represented in
byte 0.
For inputs that operate in the counter or frequency measure-
ment operating mode, the alarm signals (e.g. limit value
reached or limit value fallen below/exceeded) are represen-
ted in byte 0 (
Tab. 3/9).
In the event of a short circuit or wire break the parameterised
replacement value is issued (
Tab. 3/28 and Tab. 3/29).
Byte 1 in PII The module represents the diagnostic status of the 8 input
channels in byte 1 of the PII (
Tab. 3/9). A 1-signal indic-
ates that there is a channel error at the corresponding input
(short circuit, wire break). In the “Counter” operating mode
a 1-signal also indicates an undervoltage has been detected
that is less than or equal to 20ms. Retraction of the dia-
gnostics function is only possible by re-parameterisation or
resetting the respective counter. The user should ensure
here that the validity of the counter value is checked and
evaluated.
A 0-signal indicates that the input signal is in a signal range
that is permissible for Namur sensors.
Byte 2 to 9 in PII If the miniature switch of the module is set to ON, bytes 2 to
9 in the PII depict the current counter readings or frequency
measurements. Two bytes are occupied in the PII for each
counter or frequency measurement (
Tab. 3/9).