Applies To:
  • CitectSCADA 5.xx

The Citect SSEVEN driver for Siemens S7 PLCs uses the Siemens S7 SAPI Interface. 

Q. What does acronym SAPI mean ?
A. SAPI stands for Simple Application Programming Interface.

Q. What communications methods does the SSEVEN driver support ?
A. The SSEVEN driver supports all the communication methods that the SAPI interface does. At present, the SAPI interface supports MPI, Profibus, and Industrial Ethernet. See also Q2033 and Q2327.

Q. Which Profibus does the SAPI Interface support?
A. The SAPI interface is a layer 7 interface, as are Profibus FMS, Profibus DP etc.

Q. Can the S7 SAPI protocol be used to talk to S7 PLCs via their MPI port in a multi drop configuration ?
A. The SAPI interface supports this configuration, and hence the SSEVEN driver should support it.