Cyclic Transmission - Toshiba PA912 Instruction Manual

CAUTION

1.1.1 Cyclic transmission

As the PROFIBUS master module, the PA912 module controls slave I/O devices
(input and output devices) connected via the PROFIBUS. The PA912 is
controlled by the nv controller. The nv controller and the PA912 are connected
via the TC-net I/O loop, and they have a virtually shared memory area called
"common memory". When the output information is set in the common memory
by the nv controller, the information is outputted to the PRIFIBUS slave output
devices via the TC-net I/O loop. Similarly, the input information to the slave
input devices is inputted in the nv controller common memory via the PA912
and the TC-net I/O loop.
nv controller
（PU811）
TC-net I/O loop
common memory
Scan
transmission
TC-net I/O
loop
TC-net I/O loop with PA912 should be a single loop
configuration. When using Unified Controller type1
or Unified Controller type2 with PA912, set the "I/O
loop number" on the "module parameter"-"I/O
loop" pane of the controller to "1".
PA912
TC-net I/O loop
PROFIBUS
common memory
Output area
Maximum
768W
Input area
Maximum
768W
35W
Figure 1-2 Cyclic transmission
Unified Controller nv series PROFIBUS(PA912) Module Instruction Manual
1.1 Functions and Characteristics of the PA912 Module
PROFIBUS
slave I/O devices
Output
device
：
Output
device
Input
device
：
Input
device
RAS PROFIBUS-DP
Mandatory
I/O output
I/O output
I/O input
I/O input
5