Rockwell Automation 1747-SN Remote I/O Scanner - Manual (Page 103)

Publication 1747-UM013B-EN-P - January 2005
Specifications A-7
Determining TSNo-bt
Use the following table to find TSNo-bt for your particular
configuration.
Variable Variable Description Location of Variable
T
ps
The total processor scan
time (ms) Measured or estimated
T
RIO
The total RIO scan time (ms) see the section RIO Scan
Time Calculation (TRIO) on
page A-4
T
btx
Additional time due to
sending any BT data on the
RIO link. see the section Determining
Tbtx on page A-8
T
adp
The adapter throughput
delay. For a 1747-ASB, this
is two ASB backplane scan
times. adapter user manual
T
SNo-bt
Scanner output delay time
with BTs present see the section Determining
TSNo-bt on page A-7
T
SNi
The scanner module input
delay time (ms) 5 ms (constant value for all
formulas in this appendix)
T
id
The input module delay time
(ms) I/O product data and I/O
instruction sheets
T
od
The output module delay
time (ms) I/O product data and I/O
instruction sheets
IMPORTANT
The times shown are, to the best of our knowledge,
the maximum delay times of the scanner. However,
in instances that throughput is an important
consideration, test the application thoroughly first to
ensure proper operation. Note that in most situations
the average throughput is much better than the
calculated maximum throughput.