467
FX3G/FX3U/FX3GC/FX3UC 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
FNC30-FNC39
Rotation and
Shift
12
FNC40-FNC49
Data Operation
13
FNC50-FNC59
High-Speed
Processing
14
FMC60-FNC69
Handy
Instruction
15
FNC70-FNC79
External FX I/O
Device
16
FNC80-FNC89
External FX
Device
17
FNC100-FNC109
Data
Transfer 2
18
FNC110-FNC139
Floating Point
19
FNC140-FNC149
Data
Operation 2
20
FNC150-FNC159
Positioning
Control
Related devices
→ For detailed explanation, refer to the Data Communication Edition.
*1. Ch2 is not available in 14-point and 24-point type FX3G PLC.
Ch0 is available only in FX3G/FX3GC PLCs.
*2. Cleared when the PLC mode is changed from RUN to STOP.
*3. Available in all FX
3G/FX3GC PLCs and FX3U/FX3UC 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 FX3G/FX3GC 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
FX3U,
FX3UC-32MT-LT(-2)
RS-232C communication FX3U-232-BD or FX3U-232ADP(-MB)
RS-485 communication FX3U-485-BD or FX3U-485ADP(-MB)
FX3UC(D,DS,DSS)
RS-232C communication FX3U-232ADP(-MB)
RS-485 communication FX3U-485ADP(-MB)
FX3G
RS-232C communication
FX3G-232BD or FX3U-232ADP(-MB) (which requires FX3G-CNV-ADP)
RS-232C/RS-422 converter
*1
(FX-232AW, FX232AWC and FX-232AWC-H)
RS-485 communication FX3G-485-BD or FX3U-485ADP(-MB) (which requires FX3G-CNV-ADP)
FX3GC
RS-232C communication
FX3U-232ADP(-MB)
RS-232C/RS-422 converter
*1
(FX-232AW, FX232AWC and FX-232AWC-H)
RS-485 communication FX3U-485ADP(-MB)
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
PLC.
Ch0 is available only in FX3G/FX3GC PLCs.