Allen-Bradley 1747-SN - Throughput Introduction; RIO Network Throughput Components

SpecificationsA–2
Publication 17476.6 - July 1996
RIO throughput is defined as the time between when an input event
occurs at an I/O module in an RIO chassis to when an output event
occurs at an I/O module within the same RIO chassis. There are
three types of throughput concerning the 1747-SN Series B Scanner
and its RIO network:
• discrete throughput (time from discretely mapped input to
discretely mapped output) without block transfers (BTs) present
• discrete throughput (time from discretely mapped input to
discretely mapped output) with BTs present
• BT throughput (time from when a BT is enabled to when the BT
successfully completes)
RIO Network Throughput Components
The following components affect RIO network throughput:
• the total SLC processor scan time
• the total RIO link scan time
• adapter(s) backplane scan time(s)
• the scanner’s output delay time
• the scanner’s input delay time
• input module delay times
• output module delay times
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
When the SLC control program detects that the remote input has
been turned on (via the scanner input image), it activates the
remote output device (via the scanner output image). Throughput
is then defined as the time between when the remote input device
is activated to when the remote output turns on.
Throughput Introduction