Rockwell Automation Logix5000 Controllers Controller Information and Status Programming Manual - Manual (Page 20)

Chapter 2 Determine controller memory information
There are several ways to use logic to get memory information.
• Get memory information from the controller on page 20 .
• Choose the memory information on page 21 .
• Convert INTs to a DINT on page 22 .
Get memory information from the controller
To get memory information from the controller, execute a Message (MSG)
instruction. The following table lists configuration information for the
instruction.
On this tab For this item Type or select Which means
Configuration Message Type CIP Generic Execute a Control and Information Protocol command.
Service Type Custom Create a CIP Generic message that is not available in the list.
Service Code 3 Read specific information about the controller (GetAttributeList service).
Class 72 Get information from the user memory object.
Instance 1 This object contains one instance.
Attribute 0 Null value.
Source Element source_array of type SINT[12]
In this element Enter Which means
source_array[0] 5 Get 5 attributes.
source_array[1] 0 Null value.
source_array[2] 1 Get free memory.
source_array[3] 0 Null value.
source_array[4] 2 Get total memory.
source_array[5] 0 Null value.
source_array[6] 5 Get largest contiguous block of additional free logic memory.
source_array[7] 0 Null value.
source_array[8] 6 Get largest contiguous block of free I/O memory.
source_array[9] 0 Null value.
source_array[10] 7 Get largest contiguous block of free data and logic memory.
source_array[11] 0 Null value.
Source Length 12 Write 12 bytes (12 SINTs).
Destination INT_array of type INT[29]
Communication Path 1, slot_number_of_controller
Write Logic to Get Memory
Information
20 Rockwell Automation Publication 1756-PM015F-EN-P – October 2014