User manual

Understanding Your System
Chapter 1
1-9
Use a Classic PLC-5 processor (except the PLC-5/10 processor) in adapter
mode when you need predictable, real-time exchange of data between a
distributed control PLC-5 processor and a supervisory processor. You
connect the processors via the remote I/O link (see Figure 1.3). You can
monitor status between the supervisory processor and the adapter-mode
PLC-5 processor at a consistent rate (i.e., the transmission rate of the
remote I/O link is unaffected by programming terminals and other
non-control-related communications).
Figure 1.3
AdapterMode
Communication
1
Remote I/O Link
1771 I/O
DL40
Message
Display
Remote I/O Link
Supervisory
Processor
PLC5
Processor
in Adapter
Mode
1
The following programmable controllers can operate as supervisory processors:
PLC2/20t and PLC2/30t processors
PLC3t and PLC3/10t processors
PLC5/11, 5/15, 5/20, 5/25, and 5/30 processors as well as PLC5/VMEt processors
PLC5/40, 5/40L, 5/60, 5/60L, and 5/80 processors as well as PLC5/40BVt and
PLC5/40LVt processors
PLC5/20Et, 5/40Et
PLC5/250t
All PLC5 family processors, except the PLC5/10, can operate as remote I/O adapter modules.
2
2
The PLC-5 processor in adapter mode acts as a remote station to the
supervisory processor. The adapter-mode PLC-5 processor can monitor
and control its processor-resident local I/O while communicating with the
supervisory processor via a remote I/O link.
The supervisory processor communicates with the PLC-5/12, -5/15, or
-5/25 adapter with either eight or four I/O image table words.
A PLC-5 processor transfers I/O data and status data using discrete
transfers and block transfers. You can also use block-transfer instructions
to communicate information between a supervisory processor and an
adapter-mode processor. The maximum capacity per block transfer is
64 words.
Using the Classic PLC5
Processor
as a Remote I/O Adapter