Calculating Scan Time; Estimate Minimum Input Scan Time; Estimate Maximum Input Scan Time - Allen-Bradley 1747-OC Series User Manual

A-6 Specifications

Calculating Scan Time

1747-UM001A-US-P - March 2000
Add the rows in the following tables to calculate input and output scan
times. Fill in the shaded boxes with the correct values. All times are in
microseconds.

Estimate minimum input scan time

Discrete I/O Modules:
number of class 0 input words:
Specialty I/O Modules (Class 1)
number of 1746-BAS modules (class 1):
number of 1746-NIO4V modules:
number of 1746-FIO4V modules:
number of 1746-NI4V modules:
Specialty I/O (Class 3 and 4)
number of 1746-HSCE modules:
number of 1747-SN modules:
number of 1746-BAS modules (class 4):
Forced Input Overhead
number of class 0 input words:
number of specialty input words:
number of specialty I/O modules:
Input Scan Overhead
Minimum Input Scan Time (total)

Estimate maximum input scan time

Minimum Input Scan Time
(from above table)
Maximum Specialty I/O Input Scan Time
number of class 1 specialty I/O modules:
number of class 3 and 4 specialty I/O modules:
Maximum Input Scan Time (total)
x 48 =
x 490 =
x 265 =
x 265 =
x 325 =
x 712 =
x 1185 =
x 650 =
x 6 =
x 9 =
x 30 =
36
x 50 =
x 200 =