SEW-Eurodrive MOVI-PLC basic DHP11B-T0, Руководство пользователя

Страница: 52 / 96

5
PROFIBUS-DP Operating Characteristics
Parameter setting via PROFIBUS-DP
52
Manual – MOVI-PLC
®
basic DHP11B.. controller
Data range As shown in the following table, the data is contained in byte 4 through byte 7 of the
parameter channel. This means up to 4 bytes of data can be transmitted per service.
The data is always entered with right-justification; that is, byte 7 contains the least signifi-
cant data byte (LSB data) whereas byte 4 is the most significant data byte (MSB data).
Incorrect execution
of a service The status bit in the management byte 0 is set to indicate that a service has been
executed incorrectly. If the received handshake bit is identical to the transmitted hand-
shake bit, the MOVI-PLC
®
basic DHP11B.. controller has executed the service. If the
status bit now signals an error, the error code is entered in the data range of the param-
eter telegram. Bytes 4 ... 7 send back the return code in a structured format.(
Æ
Section
"Return Codes").
Reading a
parameter with
PROFIBUS-DP
(Read) Due to the cyclical transfer of the parameter channel, to execute a read service via the
8 byte MOVILINK
®
parameter channel, the handshake bit may only be changed if the
complete parameter channel has been set up for the specific service. As a result, adhere
to the following sequence when reading a parameter:
1. Enter the index of the parameter to be read in byte 2 (index high) and byte 3 (index
low).
2. Enter the service identifier for the read service in the management byte (byte 0).
3. Transfer the read service to the MOVI-PLC
®
basic DHP11B.. controller by changing
the handshake bit.
Since this is a read service, the sent data bytes (bytes 4...7) and the data length (in the
management byte) are ignored and do not need to be set.
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Manage-
ment
Reserved Index high Index low MSB data Data Data LSB data
High byte 1 Low byte 1 High byte 2 Low byte 2
High word Low word
Double word
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Manage-
ment
Reserved Index high Index low Error class Error code Add. code
high:
Add. code
low
Status bit = 1: Incorrect execution of a service
0 0
I