The communication between the master and the PSC-PB is illustrated in a simplified manner below:
MASTER |
|
PSC-PB |
The PSC-PB continously delivers data from the power supply to the master. The data includes the voltage and current values at the power supply's output as well as status signals - for more details see chapter "Telegram Structure" below. Hence the conditions of the power supply are made available to the Profibus master as input data. The Master can set the power supply by sending a data telegram to the PSC-PB.
The structure of the data telegram is illustrated in the table below. This structure is identical for the cyclical messages from the PSC-PD to the master (output data telegram) as well as for the cyclical messages from the Master to the PSC-PD (input data telegram). The PSC-PD goes to a safe state (0V, 0A), when the Master stops transmitting.
Byte #0 | #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | |||||||
Bit_7 | Bit_6 | Bit_5 | Bit_4 | Bit_3 | Bit_2 | Bit_1 | Bit_0 | 32 bit | 32 bit | |||||||
ACF | DCF | LIM | OT | PSOL | CC | RSD | CC (prog/mon) mA | CV (prog/mon) mV |
The data transfer is in Big Endian Format (highest bit value first). Swap the four CC- and CV bytes during read/write.
When a Profibus interface is assembled in a ES0300-0.45 type power supply the current programming and monitoring values are send in μA.
Information about the basic communication functions and diagnostics can be found in the interface GSD file. SYSD0985.zip
The PSC-PB is based on the SupplyCom interface
as designed by SysDesign
GmbH.
Profibus ident: 0x0985