Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 889

Network Instructions
856
Using Communications Instructions Inside Interrupt Tasks
If communications instructions are used inside interrupt tasks, always use
DI(693) and EI(694) to disable interrupts before and after communications
instructions using automatically allocated communications port numbers in
the cyclic tasks regardless of whether user-specified or automatically allo-
cated communications port numbers are being used in the interrupt tasks. An
example is shown below.
Cyclic Execution Task
a (executing)
DI
@Communications
instruction
Communications
port: F
@MOV
A218
b (port being used)
@MOVL
A216
e (response code
storage location)
c (standby)
EI
c (standby)
a (executing)
TST
A214
b (port being used)
Disable interrupts using DI(693) and EI(694) in cyclic tasks
when communications instructions are used in any interrupt task.
d (execution completed)
MOVL
e (response code
storage location)
IR0
Network communications
error processing
,IR0
#0000
Section 3-24