114
Function Block Editing
Section 6-3
Discrepancy Time
If the function block input type is set to Dual Channel Equivalent or Dual
Channel Complementary, the discrepancy time (i.e., the time between
changes in the inputs) can be evaluated.
The time between when one of the dual-channel inputs changes until the
other one changes is monitored. If the second dual-channel input does not
change before the discrepancy time expires, an error will occur and the Out-
put Enable output from the function block will not turn ON.
The dual channel modes can be used to detect faults in safety devices and
safety device wiring monitored by the function block.
The time between changes in the inputs will not be monitored if the discrep-
ancy time is set to 0.
The discrepancy time is evaluated both when the input signals go from active
to inactive and from inactive to active.
■
Normal Operation Example for Dual Channel Equivalent Setting
Dual channel mode
Input signals
Input signal status
Input
1
Input
2
Dual Channel Equivalent
• Input 1: NC
• Input 2: NC
0
0
Inactive
0
1
Discrepant
1
0
Discrepant
1
1
Active
Dual Channel Complementary
• Input 1: NC
• Input 2: NO
0
0
Discrepant
0
1
Inactive
1
0
Active
1
1
Discrepant
Discrepancy time
Input 1
Input 2
Discrepancy time
Output
Enable
Discrepancy Normal
Error
Summary of Contents for NE1A-SCPU01 - 07-2009
Page 3: ...iv...
Page 9: ...x TABLE OF CONTENTS...
Page 11: ...xii...
Page 15: ...xvi...
Page 70: ...35 Installation Section 3 1 Top Top Bottom Bottom...
Page 72: ...37 Installation Section 3 1 3 1 3 Dimensions and Weight Dimensions NE1A SCPU01 V1...
Page 85: ...50 Wiring Section 3 2...
Page 123: ...88 Explicit Message Communications Section 4 7...
Page 141: ...106 Safety Outputs Section 5 4...
Page 257: ...222 Connection Status Tables Section 10 8...
Page 261: ...226 NE1A series Controller Replacement Section 11 2...
Page 264: ...229 Appendix A Local Input and Test Output Setting Example Local Output Setting Example...
Page 266: ...231 Appendix A Programming Example Local Input and Test Output Setting Example...
Page 267: ...232 Appendix A Local Output Setting Example...
Page 269: ...234 Appendix A Programming Example Local Input and Test Output Setting Example...
Page 270: ...235 Appendix A Local Output Setting Example...
Page 273: ...238 Appendix A Local Input and Test Output Setting Example Local Output Setting Example...
Page 275: ...240 Appendix A Programming Example Local Input and Test Output Setting Example...
Page 276: ...241 Appendix A Local Output Setting Example...
Page 289: ...254...
Page 293: ...258 Index...