User manual

1785-UM022B-EN-P - February 2002
2-8 Planning to Use Your ControlNet PLC-5 Processor
Using Immediate Data-Transfer Operations
ControlNet Immediate Data I/O transfers—Immediate Data Input
(IDI) and Immediate Data Output (IDO)—perform similarly to the
Remote-I/O supported immediate I/O transfers—Immediate Input
(IIN) and Immediate Output (IOT)—which the ControlNet system
also supports. The logic scan is temporarily interrupted while the
most recent state of up to 64 words is read from or written to the
private memory buffer.
ControlNet Data Transfer
Private
Memory
Buffers
Housekeeping
Logic Scan
Program Scan
Data-
Table
Files
Immediate Data Transfer
= Unscheduled Data Transfer
= Scheduled Data Transfer
= NUI
Data Update