Rockwell Automation 20-COMM-Q ControlNet Adapter - Manual (Page 179)

Using Explicit Messaging 6-51
20-COMM-C/Q ControlNet Adapter User Manual
Publication 20COMM-UM003F-EN-P
SLC 500 Controller – Formatting a Message to Write a Single Parameter Using
Generic Get/Set Attribute Service
Figure 6.63 Generic Set Attribute Single Message Configuration Screen
The following table identifies the data that is required in each box to
configure a message to write a single parameter.
General Tab Example Value Description
1747-SCNR Slot
Size in Words (Send Data)
Data Table Address (Send Data)
Message Timeout
ControlNet Addr
Service
(1)
Class
Instance
(2)
Attribute
(3)
1
1
(4)
N50:0
500
2
Generic Set Attribute Single
93 or 9F (Hex.)
(5)
140 (Dec.)
9 or 10 (Dec.)
The chassis slot occupied by the scanner.
Number of words to be sent (written). Each word size is a 16-bit integer.
An unused controller data table address containing the message
instruction. This address is the starting word of the source file.
The time (in milliseconds) that the message must be completed.
The node address of the adapter connected to the drive.
Code for the requested service.
Class ID for the DPI Parameter Object.
Instance number is the same as the parameter number.
Attribute number for the Parameter Value attribute.
(1) The default setting for Service is ‘Custom’, enabling entry of a Service Code not available from the Service pull-down menu. When choosing a Service other
than ‘Custom’ from the pull-down menu, an appropriate Hex. value is automatically assigned to the Service Code box which is dimmed (unavailable).
(2) The instance is the parameter number in the drive (Port 0). To write to a parameter in another port, see DPI Parameter Object on page C-16 (Class code
0x93) or Host DPI Parameter Object on page C-30 (Class code 0x9F) to determine the instance number. For example, to write to parameter 51 of a
peripheral in Port 5 of a PowerFlex 750-Series drive, the instance would be 21504 + 51 = 21555 or 5433 (Hex).
(3) Setting the Attribute value to ‘9’ will write the parameter value to the drive’s Nonvolatile Storage (EEPROM) memory, which retains the parameter value even
after the drive is power cycled. Important: When set to ‘9’, the EEPROM may quickly exceed its life cycle and cause the drive to malfunction. Setting the
Attribute value to ‘A’ (10 decimal) will write the parameter value to temporary memory, which deletes the parameter value after the drive is power cycled.
When frequent write messages are required, we recommend using the ‘A’ (10 decimal) setting.
(4) In this example, Accel Time 1 is a 16-bit integer parameter requiring the Size in Words field to be set to ‘1’. If the parameter being written to is a 32-bit
integer, the Size in Words must be set to ‘2’. When using a PowerFlex 700S or PowerFlex 750-Series drive, Accel Time 1 is a floating point number requiring
the Size in Words to be set to ‘2’. See the drive documentation to determine the size of the parameter and its data type (16-bit or 32-bit integer or REAL).
The following page shows ladder logic to convert floating point data into integer files.
(5) See Table 6.A on page 6-2 for limitations of PowerFlex 7-Class and PowerFlex 750-Series drives when using DPI Parameter Object Class code 0x93 or
Host DPI Parameter Object Class code 0x9F for explicit messaging.