Allen-Bradley SLC 500

QUICKDESIGNER Siemens •
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RK 512 Computer Link with 3964R Procedure
Using the RK 512 computer link, data can be exchanged between the CPU 928B in an S5 135U or S5
155U and a QuickPanel. The SIMATIC S5 RK 512 computer link transmits data bytes using the 3964R
transmission procedure, which adds start and end characters to the data bytes and initiates repetitions if
errors occur. The RK 512 replies to every correctly received command message with a reply message.
Various submodules are available for the RK 512 computer link. This section describes the operation
with a TTY submodule. The TTY submodule is installed in the submodule receptacle of the second
interface of the CPU 928B. You must assign parameters to the second interface for the RK 512
computer link. You will need the DX 2, a static parameter set, and a send coordination byte (SCB).
You must enter the following information in DX 2:
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link type: RK 512 computer link
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location of the static parameter set
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location of the send coordination byte (SCB)
In the DB/DX containing the static parameter set you must enter the parameters for the physical layer
and for the data link layer.
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The parameters for the physical layer are as follows:
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transmission speed (bps)
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parity
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bit per character
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stop bits
The parameters of the data link layer, that determine the characteristics of the 3964R transmission
procedure, are as follows:
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mode: 3964R procedure with defaults or assigned values
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priority
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character delay time
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acknowledgment delay time
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connection attempts
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number of repetitions
With the send coordination byte (SCB) you can perform the following:
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reset the RK 512 computer link
You can generate the parameter set in DX2 and the static parameter set either via the DB editor or via
the menus in the COM PP Parameter Assignment Software.