The VME-PROF-M starts every DP-cycle with a „Global Control Telegram“. This can be used for synchronization the slaves. At the end of the slave data exchange a VMEbus interrupt could be generated. From this time on the VMEbus CPU can use the Dualport RAM of the VME-PROF-M for reading and writing new data. The VME-PROF-M uses this time slot for management services on the Profibus ( GAP Update and Token passing to other masters).

The DP cycle can run free (DP-V0) or can run in a fixed timing (DP-V2). We recommend to use always a fixed cycle time. The VME PROF-M controls the cycle in this case with a hardware timer at microseconds precision.

The VME-PROF-M Masters sends an output data telegram with a maximum length of 244 Bytes. The slave responds with an input data telegram also with a maximum length of 244 Bytes. The actual data length depends on the slave requirements. Profibus-DP supports modular slave stations. This includes a buscoupler and more different I/O modules. The actual slave configuration is described in configuration bytes. The master checks the agreement of the actual configuration and the configuration bytes at start-up. Only when the agreement is O.K. The slave goes in working mode.

A simple slave for example could have the following configuration:

1 analog input module with 4 channels each 16 Bits = 4 input words = 8 Byte

1 digital input module with 8 channels each 1 Bit = 1 Byte input

1 digital output module with 8 channels each 1 Bit = 1 Byte output

Together we have 1 Byte output and 9 Byte input what is totally 10 Byte user data.

The Nautibus VME-PFROF-M is a Profibus Slave Interface Module designed for integration into VMEbus-based systems. It allows devices in industrial systems to communicate via the Profibus network, a widely used fieldbus standard for control applications. The module enables seamless data exchange between control systems and field devices such as sensors, actuators, and PLCs, providing reliable and high-speed communication for industrial processes.