GE VersaPoint IC220PBI002, Руководство пользователя

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8-26 VersaPoint™ I/O System Profibus-DP NIU User’s Manual – August 2005 GFK-1911B
8
Example 5, Reading a Non-Existent Object on an I/O Module with PCP
Functions (Access to 5C00, Subindex 0 on a VersaPoint RS-232
Communications Module2, Slot 3)
Read request (master -> slave)
Data (4 Words VC1) Data Structure
01 03 5C 00 00 I 00 00 00 Read PCP/Slot/Index high/Index low/Subindex I 3
bytes unused
Read response (slave -> master) 44
hex
in the read response of the start
fragment indicates an error. 06
hex
and 07
hex
in this example are the error code,
which indicates that the addressed index does not exist, see also "Error Codes for
PCP Communication" on page7-19.
Data (4 Words VC1) Data Structure
81 44 06 07 00 00 I 00 00 Read response/Status/4 bytes of error code I 4
bytes unused
Abort request (master -> slave) Communication can be reset using 60
hex
so
that all buffers involved in the communication are set to their initial status.
Data (4 Words VC1) Data Structure
60 xx xx xx xx xx xx xx Abort
Abort response (slave -> master)
Data (4 Words VC1) Data Structure
E0 00 00 00 00 00 00 00 Abort response
Clear request (master -> slave)
Data (4 Words VC1) Data Structure
00 xx xx xx xx xx xx xx Clear
Clear response (slave -> master)
Data (4 Words VC1) Data Structure
00 00 00 00 00 00 00 00 Clear response