Custom configuration block (ccb), Chapter 3 – Rockwell Automation 1771-SPI,D17716.5.122 SPI PROTOCOL INTERFACE User Manual
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Defining Command and Status Blocks
Chapter 3
3-6
The custom configuration block (CCB) tells the SPI module the required
configuration for a single device, specified by the device ID in its header.
Your program must transfer a CCB to the SPI module for each custom
device on the SPI network. Then, your program must use custom data
blocks (CDBs) to transfer data to the devices.
Transferring custom configuration, data, and status blocks to/from the SPI
module uses fewer words and a simpler format than SPI-specified standard
blocks. However, you must still configure the SPI module with the MCC.
The SPI module stores custom configuration and data in RAM. If the module
loses power this information is lost, requiring replacement downloads.
The SPI module can store:
up to 10 CCBs for that number of devices
up to 60 bit-command words and/or setpoints per device
Table 3.E
Bit/Word Map of the Custom Configuration Block (CCB)
Word
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1
0
CA
DC
SPIĆspecified Device ID
2
Number of numeric setpoints
Number of bitĆcommand words
3
Number of bitĆstatus words
Number of ASCII strings
4
Number of ASCII status strings
Number of numeric status words
starting at
5
CMD1 Code (such as 20)
CMD2 Code (such as 49)
g
5
SPI codes CDM1 and CDM2 define the specific bitĆcommand word that your program will load into word 5 of the CDB.
If you have more codes of this type, load them in the next consecutive words. Leave no blank words.
The number of bitĆcommand words that you entered in word 2 bits 0Ć7 must be identical to the number of:
# code words (such as word 5 of this block)
# bitĆcommand words that your program will load into the CDB starting with word 5.
⇓
⇓
⇓
⇓
⇓
⇓
⇓
6
( hi h )
CMD1 Code (such as 20)
CMD2 Code (such as 31)
(or higher)
SPI codes CDM1 and CDM2 define the specific numeric setpoint that your program will load next into the CDB.
If you have more codes of this type, load them in the next consecutive words. Leave no blank words.
The number of numeric setpoints that you entered in word 2 bits 8Ć15 must be identical to the number of:
# code words (such as word 6 of this block)
# numeric setpoints that your program will load into the CDB following the bitĆcommand words.
⇓
⇓
⇓
⇓
⇓
⇓
⇓
7
( hi h )
CMD1 Code (such as 20)
CMD2 Code (such as 22)
(or higher)
SPI codes CDM1 and CDM2 define the specific ASCII string that your program will load next into the CDB.
If you have more codes of this type, load them in the next consecutive words. Leave no blank words.
The number of ASCII strings that you entered in word 3 bits 0Ć7 must be identical to the number of:
# code words (such as word 7 of this block)
# ASCII strings that your program will load into the CDB following the numeric setpoints.
⇓
Repeat for bitĆ,numericĆ,and ASCIIĆstatus codes that you want returned in the CDS during automatic polling.
⇓
64
CMD1 Code (such as 20)
CMD2 Code (such as 3C)
Custom Configuration
Block (CCB)