OPERATION MANUAL

B7A Interface Units Section 3-8
Output Ports
■ Transmission Error Flag
The corresponding Transmission Error Flag in the first word allocated to the
Unit in the CPU Unit's Auxiliary Area will turn ON for each input port, as
shown in the following table. Words A050 to A080 are allocated to Basic I/O
Unit as information words.
Example: Rack 0, Slot 0
Port where
Transmission Error Flag
error
occurred
CS1W-B7A12 CS1W-B7A02 CS1W-B7A21 CS1W-B7A22
Port 1 A05000 --- --- ---
Port 2 A05001 --- A05000 ---
Port 3 --- --- --- A05000
Port 4 --- --- --- A05001
Example: Rack 0, Slot 1
Port where
Transmission Error Flag
error
occurred
CS1W-B7A12 CS1W-B7A02 CS1W-B7A21 CS1W-B7A22
Port 1 A05008 --- --- ---
Port 2 A05009 --- A05008 ---
Port 3 --- --- --- A05008
Port 4 --- --- --- A05009
■ Transmission Error Input Status Processing
If an error occurs at an input port, the Unit will hold the status of the input bit in
the CPU Unit's I/O memory from immediately before the transmission error
occurred. When transmission returns to normal, the signals that have been
normally received will be input to the input bit.
The B7A Interface Unit does not detect transmission errors at output ports.
Detect output port transmission errors at the B7A Link Terminal that is connected
to the B7A Interface Unit.
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