Siemens SINUMERIK 802S Technical Manual page 148

Technical Appendix
6-54
Notice:
If your system (802C base line) equips with 611 drive(s) that are not configured,
the drive ready signal will not be available. The result is you can not release
emergency stop. It is possible for you either to connect a high signal to I1.7 or
simply specify MD14512[16].bit0=1, so that you can quit from emergency stop.
SINUMERIK 802S base line
Start-Up