Access Units - Mitsubishi Electric RD81MES96 User Manual

Access units

The following table shows the number of accessible device points (access units) in one process (one scanning) when
accessing the device memory in a CPU module.
The access units of a CPU module other than the following modules depend on the module type. When data inconsistency is
a problem, set the event/condition type to "Handshake".
Type of target device (series)
RCPU Programmable
controller CPU
Process CPU
C Controller module
*1 Access from a module other than an Ethernet port of an MES interface module
*2 Access via an Ethernet port of an MES interface module
Reading/writing in access units
When the number of accessed device points is equal to the access unit or less, device values in a same sequence scan are
obtained and applied.
When the number of device points exceeds the access unit, device values may be obtained from multiple sequence scans
and applied, which may cause data inconsistency.
■When data inconsistency is a problem
Set the following when a sequence program and the data needs to be synchronized and data inconsistency is a problem.
• Set the number of device points accessed at the same time to the access unit or less.
• Change the access type to high-speed access. (Only for device reading)
• Set the event/condition type to "Handshake".
Device reading
General access
*1
118 points
*2
58 points
High-speed access
8192 points
Not supported
2.2 Accessible Devices and Range
Device writing
*1
78 points
*2
38 points
2 SPECIFICATIONS
2
31