Festo PROFIBUD-DP, Elektronics Manual

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A. Technical appendix
A−10
Festo P.BE−CPV−DI02−EN en 0704NH
A.2.4 Transferring input and output data
Data_Exchange The cyclic exchange of data is accomplished with the
function Data_Exchange.
With this function the output data for CPI systems is trans
mitted as an octet string of length x. The octet string length
depends on the number of identifier bytes.
No te
With the function Data_Exchange, the CPI system expects
the
o ut p ut d a t a for the valves and electric outputs.
The
in p ut d a t a
are sent to the master as a reply telegram.
A.2.5 Read diagnostic information
Slave_Diag The diagnostic data are requested by the CPI system via the
function Slave_Diag (see section 3.2.4, Diagnosis via
PROFIBUS−DP).
Set_Prm With the function Set_Prm you can determine the watchdog
time (WD_Fact_1, Octet 2, WD_Fact_2, Octet 3). In the event
of a fault the CPI system switches off all valves and electric
outputs after the parametrized time (e. g. if there is a bus
failure).