Example - WAGO -I/O-SYSTEM 750 Series Manual

4.1.1.1

Example

Let a node contain the following modules with an input / output process
image:
3 x 750-402
1 x 750-452
1 x 750-655
1 x 750-550
1 x 750-452
1 x 750-550
1 x 750-452
1 x 750-504
By default, PDO 1 to PDO 4 are reserved for and occupied by digital and
analog modules; further PDOs are not required for digital and analog modules.
Apart from an AS-Interface master module, no further special modules are
fitted.
The AS-Interface master module occupies a process image of 12 bytes when
the mailbox size is 6 bytes. The mailbox is permanently superimposed.
The 5th PDO and the 6th PDO are therefore assigned to this module. The 6th
PDO contains only 4 bytes of process data.
The 7th PDO and the subsequent PDOs are free for further modules.
Data in the process image
Byte
Content
C/S
MB1 – MB6
D1 – D4
Entries in the object list
Sub0
Sub1
Sub2
Sub3
Sub4
Sub5
Sub6
WAGO-I/O-SYSTEM 750
I/O Modules
each with 4 bits of input data,
4 bytes of input data,
12 bytes of input data 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.
1 2 3 4
C/S -- MB1 MB2 MB3 MB4 MB5 MB6
Control / status byte
Mailbox data, byte 1 - byte 6
Process data, byte 1 – byte 4
6 (Number of sub-indices)
8 (Length of mailbox string (Sub2))
C/S - MB1
D1 (Process data flags + Slave 1/1A)
D2 (Process data Slave 2/2A + Slave 3/3A)
D3 (Process data Slave 4/4A + Slave 5/5A)
D4 (Process data Slave 6/6A + Slave 7/7A)
Fieldbus-specific behavior
5 6 7 8
MB2 MB3 MB4 MB5
• 53
CANopen
9 10 11 12
D1 D2 D3 D4
MB6