B&R Industries X20 System, Руководство пользователя

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X20 system modules • X20 electronics module communication • X20CS1070
1628 X20 system User's Manual 3.10
4.18.7.7.8.4 Read "TXCount"
Name:
TXCountReadBack
The value of "TXCount" is copied from the module into this register. This makes it possible for the application task
to verify that the CAN telegram data was transfered from the module correctly.
The meaning of the value depends on the "TxFifoInfo" bit. This is located in the Cfo_TXRXinfoFlags register
Data type Value "TxFifoInfo" bit Meaning
0 Read back "TX-Count" USINT 0 to 255
1 See bit structure.
Bit structure:
Bit Function Value Information
0 - 3 Read back "TX-Count" 0 to 15 Only the lower 4 bits
4 - 7 Number of frames in the transmit buffer that have not been trans-
mitted
0 to 15 If this number exceeds the 15 (a maximum of 18 possible), the
value 15 is returned.
4.18.7.7.8.5 Read "TXCount" from the previous cycle
Name:
TXCountLatchReadBack
This register is used to copy the "TxCount" value from the previous cycle from the module. In the event of an X2X
Link or POWERLINK transfer error, this makes it possible to determined if the error occurred on the way from
the CPU to the module or on the way from the module to the CPU (see 4.18.7.7.9.4 "Taking possible errors into
consideration when transmitting" on page 1630).
The meaning of the value depends on the "TxFifoInfo" on page 1626 bit in the "Cfo_TXRXinfoFlags" register.
Data type Value "TxFifoInfo" bit Meaning
0 TX-Count read back from the previous cycle USINT 0 to 255
1 See bit structure.
Bit structure:
Bit Function Value Information
0 - 3 TX-Count read back from the previous cycle 0 to 15 Only the lower 4 bits
4 - 7 Number of frames in the transmit buffer that have not been trans-
mitted
0 to 15 From the previous cycle
4.18.7.7.8.6 Counter for received CAN telegrams
Name:
RXCount
This counter is increased by 1 with each CAN telegram. The application task can thus detect when new data is
received and get it from the corresponding "RXData" registers.
The meaning of the value depends on the "RxFifoInfo" on page 1626 bit in the "Cfo_TXRXinfoFlags" register.
Data type Value "RxFifoInfo" bit Meaning
0 Counter for received telegrams USINT 0 to 255
1 See bit structure.
Bit structure:
Bit Function Value Information
0 - 3 Counter for received telegrams 0 to 15 Only the lower 4 bits
4 - 7 Number of unacknowledged telegrams in the receive buffer 0 to 15