Filter
Top Products
380
6-4-3 Host Link Systems
The following diagram illustrates the processing that takes place when an input
on one PC is transferred through the Host Link System to turn ON an output on
another PC. Refer to Host Link System documentation for further details.
X
Input on #0
Output on #31
Cycle time
Input
signal
Output
signal
I/O refresh
I/O refresh
I/O response time
CPU Unit reads
input signal
CPU Unit writes
output signal
Output ON delay
Input ON delay
Host link service
Buffer for Host
Link Unit # 0
Cycle time
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Command/response for Unit # 0 Command/response for Unit # 31
Host link service
The equations used to calculate the minimum and maximum cycle times are giv-
en below. The number of cycles required for each PC depends on the amount of
data being read/written.
Minimum response time = Input ON delay + Command transmission time + (Cycle time of PC for Unit #0 × 3) + Response transmis-
sion time + Host computer processing time + Command transmission time + (Cycle time of PC for Unit #31
× 3) + Output ON delay
Maximum response time = Input ON delay + Command transmission time + (Cycle time of PC for Unit #0 × 10) + Response transmis-
sion time + Host computer processing time + Command transmission time + (Cycle time of PC for Unit #31
× 10) + Output ON delay
6-4-4 PC Link Systems
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.
I/O Response Time Section 6-4