Omron 3G8F7-CRM21, User Manual

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Status Section 3-3
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4-Point Bit OUT Slave Unit
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2-Input and 2-Output Bit MIX Slave Unit
3-2-2 Access to I/O Data
There are two methods for access to I/O data: synchronous and
asynchronous.
Synchronous access Synchronous access uses access rights and ensures node-by-node
synchronicity.
It requires a waiting time of maximum one communications cycle in order to
obtain an access right.
See Section 4-1-2 for the access procedure.
Asynchronous access Asynchronous access does not use access rights. Thus it enables high speed
access to I/O data.
This type of access, however, ensures the synchronicity of every 16 bits of I/O
data.
See Section 4-1-1 for the access procedures.
3-3 Status
Status comprises two general categories: One is the Basic Status Group,
which is constantly updated in the shared memory, while the other is the
Detailed Status Group. The statuses in the latter group are read by the
application whenever necessary. The PC application issues a read request to
the CompoNet Master Board, and read the status.
3-3-1 Basic Status Group
To access to the Basic status group in the Windows operation systems, the
function CPNT_GetStatus is used.
In an OS other than Windows, the status group can be read directly from the
shared memory access.
BIT OUT area
1 2 3 0
BIT OUT area
1 0
BIT IN area
1 0