IPxxxx-B31x - User Parameters
Data format
Auto configuration (only applies to all complex devices, not necessary for digital devices)
Complex terminal data can be represented in either Intel or Motorola format, although controllers generally expect the data to be in Motorola format.
Example:
In Motorola format, an analog value from an IP3312-Bxxx is shown as 0x0016. In Intel format, the high and low bytes are exchanged, yielding 0x1600.
Updating of the process image
- Synchronous with the cycle means that the data are triggered in synchronism with the PROFIBUS image. If a PROFIBUS telegram reaches the slave, the slave copies the data into the ASIC after the answer telegram has been sent. The outputs are written immediately.
- Free running means that the data is fetched and copied into the ASIC, and that this is repeated continuously.
Free running can be used when it is necessary to transfer the input data as fast as possible to the controller. The disadvantage of this is that the data is not free from jitter. If fast outputs are needed, or if it is necessary for the inputs to be jitter-free (e.g. for fast controllers) then cyclic transmission should be selected.
Reaction to PROFIBUS errors
- Cycle is stopped. The internal data process is stopped, and the watchdog (WD) for the channels (usually 100 ms) triggers.
- Outputs become 0. Zero is written to all the outputs in a defined manner.
- Outputs remain the same. The most recently received PROFIBUS telegram and its output data is retained. A switched output, e.g. at a IP4112 with 12 ms, is retained as long as it takes to reconstruct the PROFIBUS cycle and a new value is transmitted via the process data.