Siemens SIMATIC ET 200AL, System Manual

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Programming
4.2 Programming of Time-based IO
High-precision input/output with Time-based IO
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Function Manual, 11/2019, A5E33454822-AC
4.2 Programming of Time-based IO
Introduction
To use Time-based IO, the TIO instructions must be called in an isochronous OB. The
application can also run in another OB. This allows you to shorten the runtime of the
isochronous OB.
You need the following TIO instructions according to the required task:
TIO module TIO instructions
•
TM Timer DIDQ 16x24V
• TM Timer DIDQ 10x24V
•
Per digital input, one TIO_DI or TIO_DI_ONCE for read-in
• Per digital output, one TIO_DQ for output
•
One TIO_SYNC (for up to eight TIO modules)
This section below describes the programming of the CPU for Time-based IO.
Requirements
Hardware configuration in STEP 7 (TIA Portal):
● The TIO modules are assigned to an isochronous network.
● The TIO modules are assigned to a shared process image partition.
● The process image partition is assigned to an isochronous OB.
● The TIO modules are configured for use with instructions from the "Time-based IO"
library.
Additional information on configuration of Time-based IO is available in the section Settings
for Time-based IO (Page 25).
Procedure
1. Create a TIO instruction, TIO_SYNC, in the isochronous OB.
2. Connect all TIO modules to be synchronized at the TIO_SYNC TIO instruction using
parameters HWID_1 to HWID_8.
The HWID can be found in the hardware configuration under "Properties > System
constants".
Note
Use of symbolic constants is generally preferred instead of absolute numerical values
when interconnecting.
3. Set the data update mode at the TIO_SYNC instruction at the PIP_Mode input parameter.
The description of the modes is available in the chapter Technical implementation
(Page 20).
The parameter assignment of the TIO_SYNC TIO instruction is complete.