475
FX
3G
/FX
3U
/FX
3UC
Series Programmable Controllers
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
9
R
ota
tion and
Shi
ft
12
FN
C40-FN
C49
D
ata O
perati
on
13
FNC
50-FNC
59
High-Speed
Proc
essing
14
FM
C60-FN
C69
H
andy
In
struction
15
FN
C70-FN
C79
E
xternal
F
X
I/O
De
vice
16
FNC
80-FNC
89
External
FX
Dev
ice
17
FNC1
00-
FNC10
9
Dat
a
Transfer 2
18
FNC1
10-
FNC139
Fl
oa
ting Poi
nt
19
FNC14
0-F
N
C
149
Da
ta
Operation 2
20
FNC1
50-
FNC159
Pos
itioning
Control
Related devices
→
For detailed explanation, refer to the Data Communication Edition.
*1.
Ch2 is not available in 14-point and 24-point type FX
3G
PLCs.
Ch0 is available only in FX
3G
PLCs.
*2.
Cleared when the PLC mode is changed from RUN to STOP.
*3.
Available in all FX
3G
PLCs and FX
3U
/FX
3UC
PLCs Ver. 2.30 or later.
*4.
Cleared when PLC power supply is turned from OFF to ON.
System configuration
For using this instruction, it is necessary to attach one of the products shown in the table below to the main unit.
→
For the system configuration, refer to the respective PLC Hardware Edition manual.
→
For detailed explanation, refer to the Data Communication Edition manual.
*1.
Required to use ch0 (standard built-in RS-422 port) in FX
3G
PLCs.
Differences between the RS (FNC 80) instruction and RS2 (FNC 87) instruction
Device
Name
Device
Name
ch0
*1
ch1
ch2
*1
ch0
*1
ch1
ch2
*1
M8371 M8401 M8421 Sending wait flag
*2
D8370
D8400 D8420 Communication format setting
M8372 M8402 M8422 Sending request
*2
–
−
−
M8373 M8403 M8423 Receiving complete flag
*2
D8372
D8402 D8422
Remaining number of data to be
sent
*2
–
M8404 M8424 Carrier detection flag
D8373
D8403 D8423 Monitor for number of received data
*2
–
M8405 M8425 Data Set Ready (DSR) Flag
*3
–
D8405 D8425 Communication parameter display
–
–
–
–
D8379
D8409 D8429 Time-out time setting
M8379 M8409 M8429 Time-out check flag
D8380
D8410 D8430 Header 1, 2
–
−
−
−
D8381
D8411 D8431 Header 3, 4
D8382
D8412 D8432 Terminator 1, 2
D8383
D8413 D8433 Terminator 3, 4
D8384
D8414 D8434 Receiving sum (received data)
D8385
D8415 D8435 Receiving sum (calculation result)
D8386
D8416 D8436 Sending sum
D8389
D8419 D8439 Operation mode display
M8062 M8063 M8438 Serial communication error
*4
D8062
D8063 D8438 Serial communication error code
*4
PLC
Communication type
Option
FX
3U
,
FX
3UC
-32MT-LT(-2)
RS-232C communication
FX
3U
-232-BD or FX
3U
-232ADP(-MB)
RS-485 communication
FX
3U
-485-BD or FX
3U
-485ADP(-MB)
FX
3UC
(D,DS,DSS)
RS-232C communication
FX
3U
-232ADP(-MB)
RS-485 communication
FX
3U
-485ADP(-MB)
FX
3G
RS-232C communication
FX
3G
-232BD or FX
3U
-232ADP(-MB) (which requires FX
3G
-CNV-ADP)
RS-232C/RS-422 converter
*1
(FX-232AW, FX232AWC and FX-232AWC-H)
RS-485 communication
FX
3G
-485-BD or FX
3U
-485ADP(-MB) (which requires FX
3G
-CNV-ADP)
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.
Terminator size
1 to 4 characters (bytes)
Up to 1 character (byte)
Attachment of
check sum
The check sum can be
automatically attached.
The check sum should be
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.
Used channel
number
ch0, ch1, ch2
ch1
For the RS2 instruction:
Ch2 is not available in 14-point and 24-point type FX
3G
PLCs.
Ch0 is available only in FX
3G
PLCs.