Acyclic Parameter Request - Festo CPX Series Manual

6. Parametrisation

6.3.3 Acyclic parameter request

Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH
Acyclic functions in the module parameters
The CPX module parameters byte 8 to byte 61 are used to
execute acyclic functions in the CMAX. The area is divided
into a function head that serves request control and a data
field of 50 bytes.
Byte Description
8 ... 11 Function head for request control
12 ... 61 Data range (depending on the desired function)
Currently only function 1 = Festo Parameter Channel FPC is
available which permits exchanging acyclic parameters be
tween PLC and CMAX.
The PLC transmits up to seven parameters in this data range,
while a handshake is required between PLC and CMAX.
The advantage of acyclic parametrising is that the PLC does
not need to modify the I/O data during parameter trans
mission. If the parameter does not require this, the operating
mode must not be changed and the axis must not be
stopped.
Note
With acyclic parameter transmission, ensure that the
setpoint values of a positioning task are fully transmitted
to the CMAX when the positioning task is started. If
necessary, prevent positioning tasks during the trans
mission of parameters.
6−15