Yaskawa MP900 Series Ladder Programming Manual - Manual (Page 371)

7.4 Detailed Troubleshooting
7.4.1 Operation Errors
7-8
„ Troubleshooting Method 2
You can use the following procedure to troubleshoot operation errors that occur in DWG.H (0030 hex: Invalid
real number operation (not a number)).
1.
Identify the error drawing number with the SW00154 system register and open that drawing.
2.
Check the value of the real number operation with the online monitor.
In this example, MF000000 in the DIV instruction is “************”.
“************” indicates an illegal value for a real number (not a number). If you use that value in a real num-
ber operation, the system will generate an operation error (0030 hex: Invalid real number operation (not a num-
ber)).
Operation errors can be caused by the following problems.
• A value is not set in a register (undefined data).
• A bit, integer, or double-length integer operation was performed for a register that uses the same address.
To perform real number operations, you must set real number values.
3.
Repeat step 2, above, to isolate the register that is causing the error.
INFO