Mitsubishi Electronics FX3G User Manual
475
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
16 External FX Device – FNC 80 to FNC 89
16.8 FNC 87 – RS2 / Serial Communication 2
11
FN
C30
-FN
C3
C30
-FN
C3
9
R
ota
tion and
Shi
ft
ft
12
FN
C40-FN
C40-FN
C49
D
ata O
perati
perati
on
13
FNC
50-FNC
59
High-Speed
Proc
essing
14
FM
C60-FN
C60-FN
C69
H
andy
In
struction
15
FN
C70-FN
C70-FN
C79
E
xternal
F
X
I/O
De
vice
16
FNC
80-FNC
89
External
FX
Dev
ice
ice
17
FNC1
00-
FNC10
00-
FNC10
9
Dat
a
a
Transfer 2
18
FNC1
10-
FNC139
FNC139
Fl
oati
ng Poi
nt
19
FNC14
0-F
N
C
149
Da
ta
Operation 2
20
FNC1
50-
FNC159
FNC159
Pos
itioning
itioning
Control
Differences between the RS (FNC 80) instruction and RS2 (FNC 87) instruction
Cautions
→ For other cautions, refer to the Data Communication Edition.
• Do not drive two or more RS (FNC 80) and/or RS2 (FNC 87) instructions for the same port at the same time.
• It is not permitted to use an "RS (FNC 80)/RS2 (FNC 87)" instruction and an "IVCK (FNC270) to IVMC (FNC275)",
• It is not permitted to use an "RS (FNC 80)/RS2 (FNC 87)" instruction and an "IVCK (FNC270) to IVMC (FNC275)",
"ADPRW (FNC276)", "FLCRT (FNC300) to FLSTRD (FNC305)" instruction for the same port.
• When using a header and terminator, set the data in the header and terminator to corresponding special data
register (D) before executing the RS2 instruction. Do not change the values of the header and terminator while the
RS2 instruction is being executed.
Function Changes According to Versions
The function of the FNC 87 instruction varies depending on the PLC version shown in the table below.
Item
RS2 instruction
RS instruction
Remarks
Header size
1 to 4 characters (bytes)
Up to 1 character (byte)
For the RS2 instruction, up to 4 characters (bytes) can be
specified as a header or terminator.
specified as a header or terminator.
Terminator size
1 to 4 characters (bytes)
Up to 1 character (byte)
Attachment of
check sum
check sum
The check sum can be
automatically attached.
automatically attached.
The check sum should be
attached by a user
program.
attached by a user
program.
For the RS2 instruction, the check sum can be
automatically attached to the sent and received data.
In this case, however, make sure to use a terminator in the
communication frame to be sent and received.
automatically attached to the sent and received data.
In this case, however, make sure to use a terminator in the
communication frame to be sent and received.
Used channel
number
number
ch0, ch1, ch2
ch1
For the RS2 instruction:
Ch0 is available only in FX
Ch0 is available only in FX
3G
/FX
3GC
PLCs.
Ch2 is not available in FX
3G
PLC (14-point and 24-point
type) and FX
3S
PLC.
Compatible Versions
Item
Function Summary
FX
3S
FX
3G
FX
3GC
FX
3U
FX
3UC
Ver. 1.00
or later
Ver. 1.00
or later
Ver. 1.40
or later
Ver. 2.30
or later
Ver. 2.30
or later
ch1
Data Set Ready (DSR) Flag
Data Set Ready (DSR) Flag
Turns M8405 ON when the DR (DSR)
signal of ch1 is ON.
signal of ch1 is ON.
ch2
Data Set Ready (DSR) Flag
Data Set Ready (DSR) Flag
Turns M8425 ON when the DR (DSR)
signal of ch2 is ON.
signal of ch2 is ON.