Beckhoff EL1258, Документация

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Commissioning
EL125x, EL2258 114 Version: 2.5
6.4 Basic function principles
Table of contents
• Definitions [
}
114]
- Channel [ } 114]
- Cyclic process data/PDO [ } 114]
- Parameter data/CoE [
}
114]
- Buffer [
}
114]
- Event [
}
115]
- Timestamp [ } 115]
- MTSF [
}
115]
- Macrocycle [
}
115]
- Microcycle [
}
116]
• Compatibility mode in relation to EL1252/EL2252 [ } 117]
- PDO definition [ } 118]
6.4.1 Definitions
The following section describes some basic terminology relating to the multi-timestamp function. This is
based on the explanatory notes on the
technology page [
}
16] , which must be referred to for guidance.
Channel
The EL1259, for example, has 8 input and 8 output channels. Every channel can operate independent of the
other channels and has its own buffer and its own settings in the CoE (channel-oriented programming is
supported).
Notwithstanding the channel-based parameterization (CoE, PDO), the settings for all channels are
implemented together in the terminal.
Cyclic process data/PDO
Each channel has 2 different types of cyclic PDO:
- Diagnostics/status/control values created specifically for the buffer
- The actual "values" as time-stamped Boolean data in the form of an array. The array should be set to a
suitable size in the configuration. It cannot be changed during runtime.
See also PDO overview on the commissioning pages and the following sections.
Parameter data/CoE
In the CoE each channel has a parameter range 0x80n0:ff [
}
175] with suitable settings for configuring the
buffer or the input/output behavior, for example.
See also information in the commissioning pages [
}
119] .
Buffer
Each channel has its own buffer (memory) for 32 events, based on the FIFO principle. It is served via
channel-specific PDOs - see PDO overview on the commissioning pages.
• For inputs : The channel state is queried for its switching state 0/1 based on the microcycle. Any
changes that are detected are stored in the buffer. Depending on the configured multi-timestamp factor
for the channel (MTSF), the buffer content is retrieved by the controller/PLC via EtherCAT, either in its
entirety or in several steps.
The behavior in case of a buffer overflow can be configured; an overflow of the buffer is indicated in the
process data. If necessary the buffer can be emptied by the controller.