Omron SYSMAC C200HS Operation Manual page 346

I/O Response Time
6-4-4 PC Link Systems
Caution Noise may increase I/O delays.
!
PC Link Conditions
Minimum Response Time
Cycle time
PC with
Unit 0
Buffer in Unit 0
PC Link Unit trans-
missions
Buffer in Unit 7
PC with
Unit 7
Input
Output
The processing that determines and the methods for calculating maximum and
minimum response times from input to output are provided in this subsection.
The following System and I/O program steps will be used in all examples below.
This System contains eight PC Link Units.
In looking at the following timing charts, it is important to remember the se-
quence processing occurs during the PC scan, particular that inputs will not pro-
duce programmed-actions until the program has been execution.
PC Link Unit
Unit 0
PC
Input on PC
Input
of Unit 0
Input LR XXXX
The PC Link System used in this example consists of the following:
• No. of PCs linked:
• No. of LR points linked: 128 per PC
• Maximum PC:
• LR points used:
The following illustrates the data flow that will produce the minimum response
time, i.e., the time that results when all signals and data transmissions are pro-
cessed as soon as they occur.
Program executed.
Minimum transmission time
The equation for minimum I/O response time is thus as follows:
Response time = Input ON delay + Cycle time of PC of Unit 0 + Minimum trans-
mission time + (Cycle time of PC of Unit 7 x 2) + Output ON
delay
Output on PC
LR
of Unit 7
bit
X
LR XXXX
8
8
1,024
I/O refresh
Section 6-4
PC Link Unit
Unit 7
PC
X
Output
Output
X
I/O refresh
Program
executed.
Cycle time
337