Applies To:
  • CitectSCADA 5.xx, 6.00
  • CitectHMI 5.xx, 6.00

I am using the latest S7NT driver and getting a hardware error Generic 21 (Channel off-line, cannot talk) Driver 20 or 0x14 (Channel not on-line). What is causing this error?

This can be caused by not setting the slot number in the Siemens Netpro S7-Connection configuration, Address details:

You must specify the slot number that the CPU is located in the PLC Rack. Normally for an S7-300 it is slot 2, and for a S7-400 it is slot 3.


S7NT, 0x14, Channel offline