Applies To:
  • CitectSCADA x.x

The SIDIRECT Citect device driver is a serial driver using the AS511 protocol to talk directly to the Siemens S5 series CPUs. I have used the driver with the smaller CPUs and it worked, but when I used it with the higher performance CPUs, it didn't. Why? 

The AS511 protocol varies from CPU to CPU. Most CPUs are handled by the SIDIRECT driver with no problems. The following lists the CPU models which are not supported:
  • CPU945 - Used with the S5-115
  • CPU928 - Used with the S5-135/155
  • CPU946 - Used with the S5-135/155
  • CPU947 - Used with the S5-135/155
  • CPU948 - Used with the S5-135/155

This driver is currently under modification to allow direct communications to the CPUs mentioned here. The knowledge base article will be amended when these modifications are made.