6-6
6.3 I/O Allocation
The flag information between MCU and the CPU unit is transmitted using X and Y.
For this unit, 16 I/O each for X and Y, totally 32 I/O are allocated. I/O numbers are determined
depending on the inslallation location and the I/O allocations of the other units.
I/O numbers (when the unit is installed in the slot 0) (0: OFF, 1: ON)
Input signal
COM. 1 COM. 2
Name Description
Effective
operation mode
X0 X2 Reception
done flag
When MCU completes the data reception, it
turns on.
When waiting for data reception: 0
When completing data reception: 1
X1 X3 PLC data
reception
done flag
When MRCV is completed, it is set/reset.
Reading completes: 1
No reading data: 0
Note1)
X4 X5 Transmission
done flag
When transmission is available: 1
During transmission: 0
Note2)
When transmission is completed: 1
X6 X7 Reception
error
When MRCV is completed, it is set/reset.
Errors exist in the data read=1
No error exists in the data read=0
Note1)
General-purpose
serial
communication
X8 X9 CTS signal
monitor
Status of the CTS signal sent from the
device communicating with.
Transmission is possible from MCU=0
Transmission is not possible from MCU=1
The RTS signal from MCU is controllable by
Y18 and Y19.
Effective only
when setting the
RS/CS to be valid
and using the
communication
block AFP2803
(RS232C type).
XA XC Latest
reception
error
Set when an error occurs during the
reception of data by MCU
No reception error: 0
Reception error: 1
The details of the reception error can be
confirmed by reading out them to the PLC
using MRCV instruction.
Check X6/X7 to see whether there are
errors in each receive buffer or not during
multiple reception.
General-purpose
serial
communication
(Reception)
XB XD Setting error Operation mode switch setting error
Usage restrictions for the unit (For the
details on the errors which the settings
exceed the limited values of PC link
mode/computer link mode, refer to the
exhibit.)
All operation
modes
XE XF CH reset
done
Communication channels can be reset by
turning on Y1E or Y1F. This flag is the
signal of its completion.
At completion: 1
When Y1E/Y1F is off: 0
General-purpose
serial
communication
Note1) This flag is effective after the execution of the F161 (MRCV) instruction until one of the following
instructions is executed.
1: END instruction (Beginningn of scan)
2: F161 (MRCV) instruction
3: Partial input instruction F143 (IORF)
Note2) When the transmission is completed within one scan, it may not be 0.