Burkert Type 8605 - Manual (Page 12)

12
Serial Communication
preamble 3.4.2.
The preamble consists of 2 to 20 0xFF characters. It is used to synchronize the data transfer.
Delimiter 3.4.3.
Telegrams are distinguished from each other mainly by the delimiter:
message type Short frame long frame
Master → Slave 0x02 0x82
Slave → Master 0x06 0x86
Burst message from slave 0x01 0x81
Master: PC or manual operating unit
Slave: Field device, 8605
address 3.4.4.
The address field contains both the master address and the slave address of the message. One byte is used for this
purpose in a short frame, while 5 bytes are used in a long frame. Each device must respond to a long frame address
of 0 (= broadcast address), i.e. bit 0 and bit 1 = 1 or 0, bits 2 ... 39 = 0.
The highest-order bit in both formats indicates which master is involved in communication.
(1: Primary master, continuously connected hosts;
0: Secondary master, manual operating units)
Short frame adresse (1 byte)
Bit 0 (MBS)
Master Address (m)
0: Secondary Master
1: Primary Master
Bit 1 Burst Info (b)
0: Not in burst mode
1: In burst mode
Bit 2 ... 7 (LBS) Polling Address (x) (0 ... 32), bit 4 = MSB, bit 7 = LSB
mbxxxxxx
x: Polling Address
b: Burst Info
m: Master Address
Short Frame Adresse Fig. 6:
english
Typ 8605