Rockwell Automation 1785-Vx0B, D17856.5.9 PLC-5 VME VMEbus Programmable Controllers User Manual - Manual (Page 18)

Chapter 1
Overview
1-7
Figure 1.2 illustrates the basic forms of communications. Table 1.A
summarizes these communication forms.
Figure 1.2
Basic Forms of Communications
Ladder
programs
Processor
data
Files
VME status file
1
2
3
4
5
6
7
8
9
10
11
12
13
Commands sent to the processor
Read/write accesses to the processor’s A16 registers and/or
the A24 memory block
Interrupt to a ladder program
Interrupt signalled by a ladder program
One-shot block copy into or out of processor data files
Continuous block copies into or out of processor data files
Interrupt signalling command completion
Interrupt signalling completion of one block copy
One-shot block copy into or out of processor data files as a
result of some commands sent to the processor
VMEbus SYSRESET
VMEbus SYSFAIL
VMEbus ACFAIL 1
Optional VMEbus system controller functions
1 Required by the PLC-5/VME processor. Asserted by VME power supply.