WAGO -I/O-SYSTEM 750 Technical Description page 177

The following table shows the assignment of the process image size to the
number of occupied PDOs when the mailbox is permanently superimposed
(Mode 1).
process
image size
n-th PDO
n+1-th
PDO
n+2-th
PDO
n+3-th
PDO
n+4-th
PDO
n+5-th
PDO
n+6-th
PDO
Here, the n-th PDO represents the first PDO occupied by the AS-interface
Master module. It contains the status / control byte, one empty byte and up to
six bytes of mailbox data.
If the length of the permanently superimposed mailbox is 0 bytes, then the nth
PDO only contains the status / control byte and one empty byte.
If the process image of the AS-interface Master module is 12 bytes or 20 bytes
in size, the last PDO is not fully occupied. A further module then starts with
the next PDO.
Note
When the mailbox size is 6 bytes and 62 AS-interface slaves are
connected, a process image size of 40 bytes is sufficient to transmit all
process data. The module then occupies five PDOs.
The following assignment of the process image size to the number of occupied
PDOs applies in the operating mode with suppressable mailbox (Mode 2).
WAGO-I/O-SYSTEM 750
CANopen
Input and Output Process Image
12 byte 20 byte
1 status/ 1 status/
control byte control byte
1 empty byte 1 empty byte
6 byte 6 byte
mailbox mailbox
4 byte prozess
data 8 byte prozess
(flags and data
slave 1/1A - (flags and
slave 7/7A) slave 1/1A –
4 byte empty sl. 15/15A)
(reserved)
4 byte prozess
data
free for next (sl. 16/16A –
module sl. 23/23A)
4 byte empty
(reserved)
free for next
module
Process Data Architecture for CANopen
24 byte 32 byte
1 status/ 1 status/
control byte control byte
1 empty byte 1 empty byte
6 byte 6 byte
mailbox mailbox
8 byte prozess 8 byte prozess
data data
(flags and (flags and
slave 1/1A – slave 1/1A –
sl. 15/15A) sl. 15/15A)
8 byte prozess 8 byte prozess
data data
(sl. 16/16A – (sl. 16/16A –
sl. 31/31A) sl. 31/31A)
8 byte prozess
free for next data
module (slave 1B -
slave 15B)
free for next
module
I/O Modules • 177
40 byte 48 byte
1 status/
1 status/
control byte
control byte
1 empty
1 empty byte
byte
6 byte
6 byte
mailbox
mailbox
8 byte prozess 8 byte
data prozess data
(flags and (flags and
slave 1/1A – slave 1/1A –
sl. 15/15A) sl. 15/15A)
8 byte
8 byte prozess
prozess data
data
(sl. 16/16A
(sl. 16/16A –
– sl.
sl. 31/31A)
31/31A)
8 byte prozess 8 byte
data prozess data
(slave 1B - (slave 1B -
slave 15B) slave 15B)
8 byte prozess 8 byte
data prozess data
(slave 16B - (slave 16B -
slave 31B) slave 31B)
8 byte
free for next
empty
module
(reserved)
free for next
module