Mitsubishi Electric MELSEC FX3U - Page 478

476
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
16 External FX Device – FNC 80 to FNC 89
16.1 FNC 80 – RS / Serial Communication
Related devices
→ For detailed explanation, refer to the Data Communication Edition manual.
*1. Cleared when the power is turned off and on (in FX
3G, FX3U and FX3UC PLCs).
Cleared when the PLC mode is changed from STOP to RUN (in FX
3G, FX3U and FX3UC PLCs).
*2. Cleared in the following cases:
• When the PLC mode is changed from RUN to STOP
• When the RS instruction is not driven
*3. Latched (battery backed).
*4. Cleared when the PLC mode is changed from RUN to STOP.
System configuration
To use 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.
Differences between RS (FNC 80) instruction and RS2 (FNC 87) instruction
Cautions
→ For other cautions, refer to the Data Communication Edition manual.
• RS (FNC 80) instruction can be used for ch1 only (cannot be used for ch2).
• 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)/IVDR
(FNC271)/IVRD (FNC272)/IVWR (FNC273)/IVBWR (FNC274)/FLCRT (FNC300)/FLDEL (FNC301)/
FLWR (FNC302)/FLRD (FNC303)/FLCMD (FNC304)/FLSTRD (FNC305) instruction for the same port.
Device Name Device Name
M8063
*1
Serial communication error 1
D8120
*3
Communication format setting
M8121
*2
Sending wait flag
D8122
*4
Remaining number of data to be sent
M8122
*2
Sending request
D8123
*4
Monitor for number of received data
M8123
*2
Receiving complete flag D8124 Header
M8124 Carrier detection flag D8125 Terminator
M8129 Time-out check flag
D8129
*3
Time-out time setting
M8161
*4
8-bit processing mode
D8063
*1
Error code number of serial communication error 1
D8405 Communication parameter display
D8419 Operation mode display
PLC Communication type Option
FX
3U,
FX
3UC-32MT-LT(-2)
RS-232C communication FX
3U-232-BD or FX3U-232ADP(-MB) (with FX3U-CNV-BD)
RS-485 communication FX
3U-485-BD or FX3U-485ADP(-MB) (with FX3U-CNV-BD)
FX
3UC(D,DSS)
RS-232C communication FX
3U-232ADP(-MB)
RS-485 communication FX
3U-485ADP(-MB)
FX
3G
RS-232C communication FX3G-232-BD or FX3U-232ADP(-MB) (with FX3G-CNV-ADP)
RS-485 communication FX
3G-485-BD or FX3U-485ADP(-MB) (with FX3G-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 with the communication frame to
be sent and received.