Burkert Type 8056 - Manual (Page 5)

- 5 - RS232_485_ETP_MODBUS_BU_REV02.doc
3.
DPP (DATA PACKET PROTOCOL)
3.1. INTRODUCTION TO DATA PACKET PROTOCOL
With Data Packet Protocol it is possible to communicate with the flow meter through protocols with data
packets.
The protocols with data packets available for the flow meter are BCP protocol (Basic Communication
protocol) and the ETP protocol (Encapsulated Transfer protocol)
The flow meter have two serial port, the RS 232 port and the RS 485 port.
When the aux module with the RS 232 port is present in the flow meter, the menu
«7-Communication»
have the function «RS232 pr.» for the selection of the protocol type.
When the DPP setting is selected in the function «RS232 pr.» of the m enu «7-Communication», it is
possible to send command to RS 232 port of the flow meter with the protocol BCP or with the protocol ETP.
When the flow meter have the option of the MODBUS protocol, the menu
«7-Communication» have the
function «RS485 pr.» for the selection of the protocol type.
The possible selections are MODBUS or DPP.
When the DPP setting is selected in the function «RS485 pr.» of the m enu «7-Communication», it is
possible to send command to RS 485 port of the flow meter with the protocol BCP or with the protocol ETP.
If the flow meter don’t have the MODBUS option, the function «RS485 pr.» is not present in the m enu «7-
Communication» and the default protocol type for the RS 485 port is DPP.
For the use of the commands and the structure of the BCP protocol see the relative section.
For the use of the commands and the structure of the ETP protocol see the relative section.
3.2. BCP PROTOCOL (BASIC COMMUNICATION PROTOCOL)
3.2.1. INTRODUCTION
The BCP protocol is a set of formatted commands based on an index.
It is possible to read data from the flow meter as Process data or the Data Logger and it is possible to send command
to the flow meter as the start stop batch for example.
The protocol is available for the RS 232 and for the RS 485 serial port.
3.2.2. DATA WORD FORMAT
The data bytes travelling in serial form on the communication line are enclosed in
words which have a fixed length of
10 bits:
1 START BIT
8 DATA BITS = 1 BYTE DI DATI
1 STOP BIT
Each word contains one byte of data plus additional bits which serve to synchronise and make the communication
safer. These extra bits are added automatically in the transmission phase by the transmitter integrated circuit. In the