Reading Module Access Time Intervals - Mitsubishi Q2ACPU User Manual

10. OTHER FUNCTIONS

10.8 Reading Module Access Time Intervals

The QnACPU can monitor the access interval time (The time between one access
reception and the next access reception) for intelligent special function modules, network
modules, data link modules, or GPP function. This enables to grasp the frequency of
accesses to the CPU module from external sources.
The operation for reading the module access interval time involves the following special
relay and special registers.
(1)
Number
Read module service
SM551
interval
(2)
Number
Service interval
SD550
measurement module
SD551 to SD552 Service interval time
Program example:
Program for reading the module access interval time of the special function module at
X/Y160.
Special relay
Name
When this relay turns from OFF to ON, the module access interval time for the
special function module specified in special register SD550 is read into special
registers SD551 to SD552.
ON : Read
OFF : Ignored
Special register
Name
Set the I/O number of the module whose access interval time is to be measured.
Set the I/O number of the peripheral device connected to the RS-422 interface of
the CPU module to FFFF
Also set the I/O number of the upper 2 digits in the 3-digit representation.
When SM551 is turned ON, it stores the interval time for access from the module
specified at SD550.
SD551: 1ms units (Range: 0 to 65535)
SD552: 1 s units (Range: 0 to 900, stored every 100 s)
Example: When the module access interval time is 123.4ms:
POINT
To read the access interval time for access from GPP function at another station in
the network, set the I/O number of the network module.
Description
Description
.
H
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SD551=123, SD552=400