Configuration...
Device designation
Article number
As of FW
version
...with S7-PCT
...without S7-PCT
Electronic module 4SI IO-Link
6ES7138-4GA50-0
AB0
V1.0.0
x
-
S7-1200
SM1278 4xIO-LINK MASTER
6ES7278-4BD32-0
XB0
V1.0.0
x
x
3.2
Data access of the automation system and the HMI device
Cyclic data exchange
To exchange cyclic process data between an IO-Link device and a CPU, the IO-Link data is
assigned by the IO-Link master to the previously set address ranges. The user program of the
CPU accesses and processes the process values by using these addresses. The cyclic data from
the CPU to the IO-Link device (for example, IO-Link actuator) takes place in reverse order.
Acyclic data exchange
Acyclic data, such as device parameters or events, is exchanged by means of a fixed index
and subindex area. The CPU accesses the data using system mechanisms (for example, for
online functions such as reading the status). You can use the index and subindex area to
access specific device information (for example, to re-assign parameters of the device or
master during operation).
Function blocks "LIOLink_Master" and "LIOLink_Device"
The programming of the CPU user program is another task in addition to the configuration
and parameterization of the IO-Link system and its integration into the overall automation
system.
For acyclic data exchange, you can use the function blocks "LIOLink_Master" and
"LIOLink_Device" for controllers of the S7‑300, S7-400, S7-1200 and S7‑1500 product lines.
The function block "LIOLink_Master" reads all relevant functions and access to the IO-Link
master, the function block "LIOLink_Device" reads all access to the IO-Link devices.
With the "LIOLink_Master" function block, you can save (Backup) and retrieve (Restore) the
device parameters and settings of an IO-Link master via the S7 program (master replacement
without engineering tool). A typical application is the replacement of the IO-Link master.
NOTE
Function blocks "LIOLink_Master" and "LIOLink_Device"
The function blocks "LIOLink_Master" and "LIOLink_Device" replace the functions of the previ
ously available block "IOL_CALL".
26
IO-Link system
Function Manual, 07/2022, A5E31637677-AC
Integration into the automation system
3.2 Data access of the automation system and the HMI device
