Point-to-point link via communication processors
Point-to-point link via communication processors (CPs) is an extremely powerful and low-cost alternative to bus systems.The advantage of point-to-point links over bus systems is especially significant when only a few (RS 485) devices are to be connected to the SIMATIC S7. The CPs can also easily link third-party systems to the SIMATIC S7. Thanks to the great flexibility of the CPs, different physical transmission media, transmission rates or even customized transmission protocols can be implemented.
With the S7-400 point-to-point link modules, adaptation to the physical transmission media is achieved by plugging in the relevant interface submodules, without the need for external converters.
All point-to-point communications modules use up to 4 protocol drivers which are integrated in the operating system. The CPs, like all other S7 modules, are parameterized from a programming device or PC via the central processing unit (CPU).
S7-400 communication processors
CP 440 - High-speed response with low data volumes
CP 441-1 - Low-cost with one variable interface
CP 441-2 - High-speed linking with two variable interfaces