Rockwell Automation 1771-SPI,D17716.5.122 SPI PROTOCOL INTERFACE - Manual (Page 40)

Creating Command and Status Blocks
Chapter 4
4-4
You must create one CCB for each device type on the link to define:
data layout of the CCB
number of bit-command words and their command codes
number of numeric preset words and their command codes
number of ASCII string words and their command codes
same information for status (independent of data sent)
Important: To obtain command-code pairs CMD1 and CMD2 for specifying
commands and setpoints to be sent to the device and status returned from it,
refer to the SPI Communication Protocol manual or the device manufacturer.
Specify them according to your application requirements. In this example,
command words 5-8 define data to be sent to the device via the SPI module.
Status words 9-12 define data to be returned via the SPI module.
Example CCB Worksheet
Word Write your entries in this column. (example entries in italics) Notes
1 device ID: name Dryer code 22 Enter the deviceĆtype ID.
2 # numeric preset words = 3 # bitĆcommand words = 1 Numbers that you enter in words
2 4 t t h di
3 # bit status words = 2 # ASCII strings = 0
y
2Ć4 must match corresponding
number of entries in words 5 to end
4 # ASCII status words = 1 # numeric status words = 1
number of entries in words 5 to end
of file.
Word Write your entries in this column. CMD1 CMD2 Notes
5 bit command 1 Machine mode:
turn machine on/off
20 49 Enter names of bit commands and
their specified command codes
CMD1 and CMD2. [1]
6 numeric preset 1 Temperature Setpoint 20 31 Enter names of numeric presets
d th i ifi d d d
7 numeric preset 2 Alarm, HiĆtemperature Deviation 20 33
p
and their specified command codes
CMD1 and CMD2. [1]
8 numeric preset 3 Alarm, LoĆtemperature Deviation 20 35
CMD1 and CMD2. [1]
ASCII string 1 not used in this example Enter ASCII strings and command
codes CMD1 and CMD2. [1]
Word Write your entries in this column. CMD2 CMD1 Notes
9 bit status word 1 Process Status 20 40 Enter specified status codes CMD1
d CMD2 f bit t t d [1]
10 bit status word 2 Machine Status 20 42
p
and CMD2 for bitĆstatus words. [1]
11 numeric status wrd 1 Process Temperature 20 72 Enter status codes CMD1 and
CMD2 for numericĆstatus words. [1]
12 ASCII status word 1 Device Revision Level 20 22 Enter specified status codes CMD1
and CMD2 for ASCII status [1]
[1] Leave no blank words between groups of entries. If not using a group, put the next group in its space.
Important: Status data (words 9-12 in this example) are returned to the
processor from the target device by the SPI module in Custom Data Status
(CDS), NOT in the Custom Configuration Status (CCS). They are
returned only as a result of the SPI module’s polling of devices on the link.
Custom Configuration Block
CCB, to Configure the SPI
Module for a Device