Specifications

App - 69
Functions
(1) This instruction reads receive data (for the fixed buffer communication) from the
connection specified by (S1) for the module designated by Un.
(D1)
No.1
No.n
No.16
BUFRCV
PLC CPU
Receive data length
Receive data
Ethernet module
Fixed buffer
External device
(2) Whether or not the BUFRCV instruction has been completed can be checked by the
complete bit devices (D2) + 0 and (D2) + 1.
(a) Complete bit device (D2) + 0
Turns on at the END processing of the scan where the BUFRCV instruction is
completed, and turns off at the next END processing.
(b) Complete bit device (D2) + 1
Turns on and off depending on the completion status of the BUFRCV
instruction.
•
Normal completion : Stays off and does not change.
•
Abnormal completion : Turns on at the END processing of the scan where
the BUFRCV instruction is completed, and turns off
at the next END processing.
[Operation when the BUFRCV instruction is being executed]
Sequence program
Complete device
Complete device +1
END
processing
END
processing
END
processing
Scan Scan Scan
Instruction execution
Abnormal completion
BUFRCV instruction
Receive data
(3) The ZP.BUFRCV instruction is executed when the read instruction (indicated by a
bit for the applicable connection in the fixed buffer receive status signal storage
area (address: 5005
H) of the buffer memory) switches from off to on.
(4) When reading receive data from the same connection, this cannot be used together
with BUFRCVS instructions (for interrupt programs).