Example - WAGO I/O-SYSTEM 750 Manual

With a masked or unmasked mailbox, the following allocation of the process
image size to the number of busy PDOs applies.
Table 35: Allocation of the process image size to the number of busy PDOs
Process
image
size
no. PDO
n+1st
PDO
n+2nd
PDO
n+3rd
PDO
n+4th
PDO
n+5th
PDO
n+6th
PDO
The 1st PDO contains a control/status byte, an empty byte and six bytes of
mailbox data with an unmasked mailbox or the first six bytes of the process
data. The following PDOs contain the remaining process data.
Note
If the mailbox is unmasked, the first six bytes of process data cannot be
accessed.
If the process image size of the Bluetooth
completely occupied. Another module then begins with the next PDO.

5.1.1.1 Example

A node contains the following modules with input/output process image:
3 x 750-402
1 x 750-452
1 x 750-644
1 x 750-550
1 x 750-452
1 x 750-550
1 x 750-452
1 x 750-504
WAGO-I/O-SYSTEM 750
I/O Modules
12 bytes
1 control/status byte
1 empty byte
6 bytes of mailbox or
6 bytes of process data
4 bytes process data
4 bytes empty (reserved)
free for next module
-
-
-
-
for every 4 bits of input data,
4 bytes of input data,
12 bytes of input and 12 bytes of output data,
4 bytes of output data,
4 bytes of input data,
4 bytes of output data,
4 bytes of input data,
4 bits of output data.
Fieldbus-specific Additions
24 bytes
1 control/status byte
1 empty byte
6 bytes of mailbox or
6 bytes of process data
8 bytes of process data
8 bytes of process data
free for next module
-
-
-
®
module is 12, the last PDO is not
• 83
CANopen
48 bytes
1 control/status byte
1 empty byte
6 bytes of mailbox or
6 bytes of process data
8 bytes of process data
8 bytes of process data
8 bytes of process data
2 bytes of process data
8 bytes empty (reserved)
free for next module