Burkert Type 8056 User Manual
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RS232_485_ETP_MODBUS_BU_REV02.doc
EXAMPLE:
want to send the command 00H to a measuring device located at address 11H (17 decimal).The device
that interrogates the network has the address FFH (255 decimal). The block to send will be composed thus
address of the measuring device to interrogate (ADDRESS TO)
|
| address of the device that interrogates the network (ADDRESS FROM)
| |
| | command for reading TYPE of INSTRUMENT (COMMAND)
| | |
| | | data block length (LENGTH)
| | | |
| | | | checksum of the entire block (CRC CHECKSUM)
| | | | |
11H FFH 00H 00H 84H
The reply from the measuring device will be the following:
address of the device that interrogated the network and which now must receive the reply (ADDRESS TO)
|
|
address of the measuring device which sent the message (ADDRESS FROM)
| |
|
|
command for reading the TYPE of INSTRUMENT + 80H (128 dec.) (COMMAND)
|
| |
|
|
|
length of the data block (=10 bytes) (LENGTH)
|
| | |
|
|
|
|
type of instrument («ML 200»)
|
| | | |
|
| | | | versione
software
(major.minor)
|
| | | | |
|
|
|
|
|
| hardware / software enabling flags
| | | | |
| |
| | | | |
| | CRC CHECKSUM)
| | | | |
| | |
FFH
11H 80H 0AH 4D 4C 20 32 30 30H
01 02H
C0 08H
21H
The measuring device has replied that it is an ML200, that its software version is the 1.02, that it has enabled the
RS485 serial port, that the output is 4..20mA and that it is using impulse emission on channel 1 (this last information is
taken from the hardware / software enabling flags).
3.2.8.
READING PROCESS DATA FROM ML210
The process data is contained in a memory block which the user can request whole or in part, depending on the
content of the two command control bytes. Byte 0 (offset) indicates which will be the first data byte of the block to
send, whilst byte 1 specifies the number of successive data bytes we want. In this way we can obtain exactly the data
we want or several pieces of data at the same time.
Command code:
01
Command format: ADDRESS TO
+ ADDRESS FROM
+ 01H
+ 02H
+ byte 0: offset – start of block to transmit
+ byte 1: length of block to transmit
+
CRC
CHECKSUM