Rockwell Automation 1769-SM1 Compact I/O to DPI/SCANport Module - Manual (Page 155)

SCANport Objects D-11
The table below lists parameters for Scattered_Link_Reference_Read
and Scattered_Link_Reference_Write object-specific services.
Important: The STRUCT may repeat up to 55 times in a single
message.
SCANport Pass-Through Link Object
(Continued)
Name Data Type Description
Scattered Link Read/Write STRUCT of
Parameter Number
WORD Parameter to read or write
Parameter Link Reference WORD Parameter value to write (zero when reading)