Allocations For The Cpu Unit - Omron CS1W-MCH71 Operation Manual

Allocations for the CPU Unit

7-3 Allocations for the CPU Unit
7-3-1 Allocations for the CPU Unit
CIO Output Area for the
Unit (CPU → MC Unit, 12
words)
396
• If the output time of the signal output from either Unit (CPU or MC) is
shorter than the processing cycle of the other Unit to which the sig-
nal is input, the latter Unit may not be able to detect the change of
the signal.
• To notify the change of the signal steadily, which is required when
starting the motion program of the MC Unit from the CPU Unit, or in
similar cases, it is necessary to make the start signal ON output time
longer than the Unit Cycle of the MC Unit. To do so, handshake pro-
cessing, such as that the start signal will be turned OFF observing the
status of the bit [Motion program operating] output from the MC Unit,
has to be executed. Note that, however, the status bit [Motion program
operating] will be turned OFF when execution of the motion program is
completed. Therefore, make sure that the Unit Cycle of the MC Unit is
longer than the Cycle Time of the CPU Unit even when the number of
commands in a program is small. Dwell Time (DWELL) command can
be used in that case, for example.
The symbols in the following tables indicate as below:
0: The bit is OFF.
1: The bit is ON.
↑ : Rising from 0 to 1.
↓ : Falling from 1 to 0.
Decimal system is applied to the other values using multiple bits.
When controlling with the rise (or fall) of the bits from the CPU Unit to the MC
Unit, the change of bits is processed in the MC Unit, not in the CPU Unit.
Therefore, if instructions like DIFU/DIFD are used, the change of bits may not
be reflected.
Section 7-3