Siemens SINUMERIK 840D sl Function Manual page 321

2.7 PLC status
PLC status signals can be checked and altered via the operator panel in the "Diagnostics"
operating area.
Application
The end customer or service personnel can use this function on site without a programming
device to do the following:
• Check the input and output signals of the PLC I/Os.
• Carry out limited troubleshooting
• Check the interface signals for diagnostic purposes.
Operation
For information about status display operation and changing PLC signals, refer to the
Operator's Guide for the relevant HMI software.
Status display
The status of the following data can be displayed on the operator panel.
• Interface signals from the machine control panel
• Interface signals to the machine control panel
• Interface signals between the NCK and PLC
• Interface signals between the HMI and PLC
• Data blocks (DB 0-127)
• Flags (FB 0-255)
• Timers (T 0-127)
• Counters (C 0-63)
• Inputs (IB 0-127)
• Outputs (QB 0-127)
For a breakdown of the interface signals (DBx, DBBy), refer to:
References:
/LIS2/ Lists (Volume 2)
Change in status
The status of the above signals can be changed for test purposes. Signal combinations are
also possible. A maximum of ten operands can be altered at any one time.
Basic logic functions: Diagnostic tools (D1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed description
2.7 PLC status
39