Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 131)

Publication 1747-UM006B-EN-P - June 2003
Specifications A-3
In the following example, the input event occurs at a discretely
mapped I/O module. The input image of I/O module is read by the
1747-ASB module during a 1747-ASB module backplane scan. The
input data is placed into a buffer, which is next read by the scanner
during a discrete scan of the RIO link. Once the input data is read by
the scanner, it is sent to and read by the PLC or SLC processor.
The response or output data travels back across the RIO link to the
1747-ASB module during a discrete scan. The 1747-ASB module
writes the output data to a discretely mapped output module during a
1747-ASB module backplane scan. The output data exits the chassis
via the I/O module in order to control the field device.
Remote Expansion Chassis
SLC Local Chassis
Remote Chassis
Scanner
Processor I/O Module
Output Device
I/O Module
Input Device
Outputs from Modules
Inputs to Modules
Outputs to Modules
Inputs from Modules
RIO Scan
ASB Module
ASB Backplane Scan
Processor Scan
Scanner Scan
PLC Local Chassis
Processor/Scanner
Processor Scan
Remote Expansion Chassis Remote Chassis
I/O Module
Output Device
I/O Module
Input Device
Outputs from Modules
Inputs to Modules
Outputs to Modules
Inputs from Modules
RIO Scan
ASB Module
ASB Backplane Scan