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Protocol implementation allows reading data in just one data block of the 3964 protocol (the protocol is s a specification of line the link layer, the transport layer is the matter of the PLC application software). Connection The connection is periodically initialized by Simatic, the process the D2000 KOM process confirms and takes over the data block according to the specification of the 3964 protocol. Data block initialization in PLC Simatic must be programmed in the STEPS5/7 programming language according to a particular CP communication module documentation.
The 3964 protocol has two variants - 3964 and 3964R. The 3964R allows extra data security using a BCC checksum.
For complex reading or writing of data into PLC Simatic, we recommend you to use the protocol RK512using the Siemens SIMATIC RK512 protocol.
| Kotva |
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| komunikacna_linka |
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| komunikacna_linka |
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Communication line configuration
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| Kotva |
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| komunikacna_stanica |
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| komunikacna_stanica |
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Communication station configuration
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- Communication protocol: Siemens SIMATIC 3964(R).
- There is not required any address parameter, No address is specified, only a single Simatic PLC can be attached to one communication line allows to communicate with one PLC Simatic.
Station protocol parameters
The Communication station dialog box - tab Protocol parameters.
Parameters defined in the input field have an effect on some optional protocol parameters. The following station protocol parameters can be defined:
Table 1
| Parameter | Meaning | Unit | Default value |
|---|
|
Delay | The delay between the response |
readings | readings till its finalization. | ms | 50 ms |
|
Repetition count of response readings | The maximum number of retries of the response reading till its finalization. | - | 600 |
| Enable the 3964 protocol, i.e. version with no transmission security using the checksum. By default, |
there is used use of | the BCC checksum is used. | YES/NO | NO |
I/O tag configuration
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Possible I/O tag types: Ai, Ci, Di.
I/O tag address is a character string as follows:
| Format | Meaning |
|---|
| DWm | WORD type value (16 bits) included in received data block on the m word-offset (offset is counted from 0). Value is converted as a signed number in case of the I/O tag type of the Ai type or as an unsigned number in the case of the Ci type. |
| DLm |
Left bit | The left byte value of WORD placed on the m word-offset. Possible I/O tag values are Ai or Ci. |
| DRm |
Right bit | The right byte value of WORD placed on the m word-offset. Possible I/O tag values are Ai or Ci. |
| Dm.n | Binary address, the value of the n bit (n is within the range 0...15) of WORD placed on the m word-offset. Possible I/O tag type is Di (or Ai and Ci, if get the values of 0/1). |
Literature
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- Ver. 1.0 - January 24th, 2002 - document creation.
- Ver. 1.1 - November 3rd, 2010 - document update.
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