Siemens SIMATIC 3964(R) CW communication
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protocol
Supported device types and versions
Communication line configuration
Line protocol parameters
Communication station configuration
I/O tag configuration
Literature
Changes and modifications
Document revisions
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On the link layer, this protocol implements the Siemens SIMATIC 3964R protocol and uses it to read from and write to the PLC. The protocol only supports database block (DB) addressing 0-255.
The protocol contains the following header defined by Control Web:
| Byte | Name | Description |
|---|---|---|
| 1 | Id | Zone identifier ('D' = data block) |
| 2 | DB | Number of zone (data block) |
| 3-4 | DW | Word address within a zone (lower byte, upper byte) |
| 5 | Cmd | Command ('R' - reading, 'W' - writing) |
| 6-7 | Count | Number of read / written words (lower byte, upper byte) |
The protocol supports reading data from control PLC automats of Siemens SIMATIC of the S5 and S7 series. PLC Simatic must be equipped with the serial communication point-to-point modules - for more details see the decription of Siemens SIMATIC 3964(R) protocol.
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