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7 SSI Input Units
NX-series Position Interface Units User’s Manual (W524)
7-9 Functions
7
7-9-8 Error Data Detection
You can separate out error data based on the difference between the previous and current present val-
ues.
Data is treated as error data if the difference between the previous and current present values is
greater than the value set for the Position Variation Limit parameter.
Error data is discarded and the present position of the encoder is not refreshed.
The following data is also not refreshed:
• Data Refresh Status bit
• Encoder Present Position Refresh Count
• Time Stamp
Any time error data is detected with this function, the error code in the SSI Status parameter is updated.
Precautions for Correct Use
Error data detection is possible only when the coding method is set to change binary codes to
present values or change gray codes to present values. Otherwise, this function is disabled.
7-9-8 Error Data Detection
Parameter name Setting Default Remarks
Position Variation
Limit
0 to 2147483647 0 • Set this parameter to 0 to disable the
function.
• Changes are applied when the power
supply to the NX Unit is turned ON or the
NX Unit is restarted.
Binary data
+
-
Conversion to
Present Value
Previous binary data
+
+
Previous present value
Encoder present position (input area)
Position
variation limit?
Y
N
Data is discarded.