Communication Path - Extended Process Image - Siemens SIRIUS M200D Manual

Functions
3.9 Communication
3.9.1.3

Communication path - Extended process image

CTT2 transfer is used for transferring serial data sets between the AS-i master and slave.
Dependent on configuration, the M200D AS-i Standard always differentiates between two
possible mechanisms:
1. Transfer of the "extended process image" of 4 bytes.
In the description of the AS-i system, this mechanism is used to transfer analog data.
M200D uses these 4 bytes for parameter assignment, diagnostics, or measured value
data, see the table Extended process image (Page 123).
2. Transfer of pre-defined data sets
see the description of data sets (Appendix A1 (Page 159)).
Reading out acyclic data sets:
• Device diagnostics reduced
• Measured values reduced
• Statistical data
• Device parameters
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Writing acyclic data sets:
• Device parameters reduced
• Command data set
M200D AS-Interface Standard
Manual, 08/2014, A5E02548958A/RS-AA/004