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

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5
PROFIBUS-DP Operating Characteristics
Parameter setting via PROFIBUS-DP
Manual – MOVI-PLC
®
basic DHP11B.. controller
51
Management of
the 8 byte
MOVILINK
®
parameter channel
The entire procedure for setting parameters is coordinated using management byte 0.
This byte provides important service parameters, such as the service identifier, data
length, version and status of the service performed.
The following table shows the structure of the 8 byte MOVILINK
®
parameter channel.
• Bits 0, 1, 2 and 3 contain the service identifier. These bits determine which service is
to be executed.
• Bits 4 and 5 specify the data length in bytes for the write service. The data length
should be set to 4 bytes for the MOVI-PLC
®
basic DHP11B.. controller.
• Bit 6 serves as the handshake between the higher-level controller and the MOVI-
PLC
®
basic DHP11B.. controller. Bit 6 triggers the implementation of the transmitted
service in the control card. In PROFIBUS-DP, the parameter channel is transmitted
cyclically with the process data. For this reason, the implementation of the service in
the MOVI-PLC
®
basic DHP11B.. controller must be triggered by edge control using
handshake bit 6. For this purpose, the value of this bit is altered (toggled) for each
new service that is to be executed. The MOVI-PLC
®
basic DHP11B.. controller uses
handshake bit 6 to signal whether the service was executed or not. The service was
executed if the handshake bit received in the controller is identical with the trans-
mitted handshake bit.
• Status bit 7 indicates whether the service was carried out properly or if errors
occurred.
Index addressing Byte 2: Index high and byte 3: Index low determines the parameter read or written via
the fieldbus system. The parameters of the MOVI-PLC
®
basic DHP11B.. controller are
addressed with a uniform index regardless of the connected fieldbus system.
Byte 1 is reserved and must always be set to 0x00.
7 / MSB 6 5 4 3 2 1 0 / LSB
Service identifier
0000 = No service
0001 = Read parameter
0010 = Write parameter
0011 = Write parameter volatile
0100 = Read minimum
0101 = Read maximum
0110 = Read default
0111 = Read scale
1000 = Read attribute
Data length
00 = 1 byte
01 = 2 bytes
10 = 3 bytes
11 = 4 bytes (must be set)
Handshake bit
Must be changed on every new task in cyclical transmission.
Status bit
0 = No fault in service execution
1 = Fault during execution of service
0 0
I