User guide

2. I/O data and sequence control
2−7
Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH
2.2 Structure of the cyclical I/O data in the operating modes
Data Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8
Output
data
Bytes 1 and 2 (fixed)
are retained in every
operating mode
(except byte 2 for
parametrisation).
The
y
contain control
Bytes 3 to 8 depend on the selected operating mode (direct mode,
record select) and transmit further control and status bytes (e.g.
CDIR, SDIR,...), as well as setpoint and actual values:
 Record number or setpoint position in the output data
 Feedback of actual position and record number in the input data
 Additional o
p
eratin
g
mode− and control mode−de
p
endent set
Input
data
They
contain
control
and status bytes
(e.g. CCON,
SCON, ...) for enab
ling the CMAX and
setting the operat
ing modes
Additional
operating
mode−
and
control
mode−dependent
set
point and actual values
Procedure
First define the operating mode in the CCON control byte. See
sections 2.2.1 and 2.2.2.
This results in the assignment of the other control and status
bytes:
 Record select mode, see section 2.2.3.
 Direct operating mode, see section 2.2.4.
 Commissioning mode, see section 2.2.5
 Parametrising mode, see section 2.2.6.
Recommendation: During operation, set the control
bit
CCON.LOCK. This way, the PLC can ensure that the pro
grammed sequence cannot be disturbed by access with
the FCT.
Evaluate the status bit SCON.FCT_MMI, and take the missing
control access into consideration in the program sequence of
the PLC.