7.3 Operation
7.3.5 How to Determine Input Error
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7.3.5 How to Determine Input Error
( 1 ) How to Determine an Input Error Using an Application Program
If it is determined that an input error has occurred, error processing, such as discarding the input data, must be imple-
mented.
[ a ] Master Side
An example of an application which checks an input error is shown in the next page.
[Conditions] Use MP2200/CPU-02. SVB-01 is attached to the slot 1 of rack 1.
MP2300S is assigned to st#1
INPUT: IW0000 SIZE: 15W
OUTPUT: OW0010 SIZE: 15W
c Check S register “I/O Error Status”
Checks whether the bit of a station mapped to the MP2300S is turned ON in the I/O error status of
a slot attached with SVB. ON indicates that an input error has occurred.
When an input error occurs, the entered data is cleared to zero.
↓
d Check “Slave Status”
Checks that the second word “Slave Status” of an input register assigned to the MP2300S is in the
following state:
bit1 WARNG = OFF
bit2 CMDRDY = ON
bit7 SYNC = ON (only when slave synchronous mode is enabled)
Otherwise, a command error is issued by a master, or a slave operation error may occur.
↓
e Check the scan counter
Checks that the first word “Scan Counter” of an input register mapped to the MP2300S is updated
based on the rules decided by an application.
If not updated normally, an operation error on the slave side may occur.
Register Meaning Remarks
DW00001 Copy of slave status −
DW00002 Condition check result −
DW00003 Copy of current value of scan counter −
DW00004 Previous value of scan counter −
DW00005 Data for checking scan counter −
DW00007 Input error counter value
Increased by one when an input error is
detected.
DW00008 Error counter value of slave status
Increased by one when an error of the slave sta-
tus is detected.
DW00009 Error counter value of a scan counter
Increased by one when an error of the scan
counter is detected.
DW000010 Copy of input data (data 1) −
•
•
•
•
•
•
−
DW000022 Copy of input data (data 13) −
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