Function Diagram

Send Mesage Q

Read Registers

Read Analog Inputs

Read Coils

Read Digitial Inputs

Send Mesage Q

For Each Link
For Each PLC

Modbus Scan Task

Driver Support

Read_bo
Write_bo
Read_bi
Read_ao
Write_ao
Read_ai

Include link, plc
and card into scan
list. For outputs,
queue the output
message.

L O S A L A M O S N A T I O N A L L A B O R A T O R Y
Operated by the University of California for the US Department of Energy