Host system
CP
Byte
Function
Byte
Function
t
0
Acknowledgement / Status
with n = number of used bytes in the address area (IO-Size)
Bit 3...0
n
8h: Idle state - no data available
n
Ah: Transfer last fragment
n
Bh: Execute a reset on the CP
Bit 7...4
Reserved for receipt
Enter here the user data for the serial communication.
Bit 3...0
Reserved for receipt
Bit 7...4
n
8h: Acknowledgement: Idle state
n
Ah: Acknowledgement: Last fragment received
n
Ch: Status: Reset was executed on the CP
n
Dh: Status: The entered length is not valid
n
Eh: Status: Error in CP communication
–
there is no response of the other station
4.3.2 Receiving data
When receiving data from the CP, the data are automatically transferred to the input area
of the host system.
Depending on the length of the received data, the telegram is transferred to the host
system as one fragment or with multiple fragments.
The fragmented transfer is started by copying bit 3 ... 0 of byte 0 of the input area to bit
7 ... 4 of byte 0 of the output area. Possible errors during the transfer may be found in
RetVal.
Host system
CP
Byte
Function
Byte
Function
u
0
Info-Byte
1
Telegram-Info-Byte
2
Length high byte
3
Length low byte
[4]
Offset high byte
[5]
Offset low byte
6
RetVal high byte
7
RetVal low byte
Control-Byte
User data
Acknowledgement Status
Principle of communica-
tion without fragmentation
VIPA System SLIO
Deployment
Principal communication via back plane bus > Receiving data
HB300 | CP | 040-1CA00 | en | 18-28
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