Refresh Timing - Omron SYSMAC CS Series Programming Manual

Basic Concepts

2-1-10 Refresh Timing

Cyclic Refresh
Immediate Refresh
Instructions with Refresh
Variation (!)
The following methods are used to refresh external I/O.
• Cyclic refresh
• Immediate refresh (! specified instruction, IORF instruction)
Every program allocated to a ready cyclic task or a task where interrupt condi-
tion has been met will execute starting from the beginning program address
and will run until the END(001) instruction. After all ready cyclic tasks or tasks
where interrupt condition have been met have executed, cyclic refresh will
refresh all I/O points at the same time.
Note Programs can be executed in multiple tasks. I/O will be refreshed after the
final END(001) instruction in the program allocated to the highest number
(among all ready cyclic tasks) and will not be refreshed after the END(001)
instruction in programs allocated to other cyclic tasks. Execute an IORF
instruction for all required words prior to the END(001) instruction if I/O
refreshing is required in other tasks.
I/O will be refreshed as shown below when an instruction is executing if an
real I/O bit is specified as an operand.
Units
C200H Basic I/O Units (CS Series only)
CJ Basic I/O Units
• When a word operand is specified for an instruction, I/O will be refreshed
for the 16 bits that are specified.
• Inputs will be refreshed for input or source operand just before an instruc-
tion is executed.
• Outputs will be refreshed for outputs or destination (D) operands just after
an instruction is execute.
Add an exclamation mark (!) (immediate refresh option) in front of the instruc-
tion.
Units Refreshed for I/O REFRESH Instruction
Location CPU or Expansion I/O Rack (but not SYSMAC BUS Slave Racks)
Units Basic I/O Units
Special I/O Units
Note C200H I/O Units cannot be mounted to CJ-series PCs.
Refreshed data
I/O will be refreshed for the 16 bits con-
taining the bit.
CS/CJ-series Basic I/O
Units
C200H Basic I/O Unit (See
note.)
C200H Group-2 High-den-
sity I/O Units (See note.)
Section 2-1
Refreshed
Refreshed
Not refreshed
Not refreshed
37