Sartorius PR 5210/10 - Write Window (Input Area); Read Window (Output Area); Data Reading and Writing

Profibus Interface PR 5210 Operating Manual
42 Sartorius
6.1.1 Write window (Input area)
Byte 0 Write data: MSB
Byte 1 "
Byte 2 "
Byte 3 Write data: LSB
Byte 4 Read_Value _Select
Byte 5 Write_Value _Select
Byte 6 Direct control bits
In this window, data are transmitted from master to slave
(PR 5210).
The first four bytes are used only for writing a data value.
The register number is written in byte 5.
Bytes 6 and 7 contain bits in direct access independent of
the write data.
After a 0-1 transition of the relevant bit, the command is
executed.
Byte 7 Direct control bits
6.1.2 Read window (Output area)
Byte 0 Read data: MSB
Byte 1 "
Byte 2 "
Byte 3 Read data: LSB
Byte 4 Read_Value _Selected
Byte 5 General system bits:
- Write_Active
- Power_fail
- ADU_Error ....
Byte 6 Status bits
In this window, data are transmitted from slave (PR 5210)
to master.
The first four bytes are used for reading a data value.
The register number is mirrored by the write window in
byte 4, when the data are available.
Bytes 5, 6 and 7 contain status bits independent of the
read data.
Byte 7 Status bits
6.1.3 Data reading and writing
The number of data exceeds the size of the write/read windows by far. Therefore, the datas are
addressed with
Write_Value_Select and Read_Value_Select . For this purpose, the first six bytes of the
write window and the first five bytes of the read window are required. Thus the master can describe
data in PR 5210: e.g. a limit value shall be set to 100kg. Weight values or other data can also be read
out of the PR 5210 by the master. For this, the write and the read window are always required.
Thereby, safe data exchange is ensured by a write and a read procedure.
For reading status bits and writing direct control bits, however, no procedure is required. The general
system bits and the status bits are always present and need not be requested. The direct control bits
are also continuously available.
Procedure for data reading:
1. Write the register number into byte 4 of the write window
(e.g. net weight) as a Read_Value
_Select.
2. Wait, until in the byte 4 of the read window
, the Read_Value _Selected is equal to the Read_Value
_Select
in the byte 4 of the write window.
3. Now, the value is available in byte 0 to 3.
Procedure for writing data:
1. Wait, until
Write_Active = 0 in the read window (ready to receive new data).
2. Write value in byte 0 to 3.
3. Write register number in byte 5 (
Write_Value_Select )
4. Wait, until
Write_Active = 1 (acknowledges data reception)
5. Write 0 into byte 5 (
Write_Value_Select ) -> Write_Active will go to 0.