Rockwell-automation 1771-SPI,D17716.5.122 SPI PROTOCOL INTERFACE Manual de usuario descargar pdf (Pagina 30)

Defining Command and Status Blocks

Chapter 3

3-8

Custom data blocks (CDBs) are used with custom configuration blocks

(CCBs) blocks to communicate with devices on the SPI network via the

SPI module. For a specified device on the SPI network, the custom

configuration block (CCB) tells the SPI module:

the type of data in each word, specified by SPI command-code pairs

the location of data, specified by word number

the order in which it will store the data

Custom data blocks must obey the “specs” of custom configuration blocks.

Table 3.G

Word/Bit

Map of the Custom Data Block (CDB)

Word 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

1 0 DC SPIspecified Device ID

2 Zone Address (for temperature control devices, only) Device Address

3 and 4 0 0 0 0

starting at

Load bitcommand words for BTW to the SPI module whose code(s) you specified in the CCB block. [ 1 ]

(If you specified none in the CCB block, start loading numeric setpoints here.)

::::::

two words Load numeric presets for BTW to the SPI module whose code(s) you specified in the CCB block. [ 1 ]

(Numeric setpoints are 32bit words, equivalent to 2 PLC words)

::::::

two words Load ASCII strings for BTW to the SPI module whose code(s) you specified in the CCB block. [ 1 ]

(ASCII strings are 32bit words, equivalent to 2 PLC words)

[ 1 ]:

Command words that you load in this CDB must match the SPI command codes that you loaded in the CCB.

They must match in type, quantity and order. Otherwise, the SPI module declares a fault.

Custom Data Block (CDB)

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 ... 61 62

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Rockwell-automation 1771-SPI,D17716.5.122 SPI PROTOCOL INTERFACE Manual de usuario Pagina 30