Contents Of Set Items In Each Control Procedure (Protocol) - Mitsubishi Electric FX3U-232-BD User Manual

FX Series PLC User's Manual - Data Communication Edition
Computer Link
6.4.3

Contents of set items in each control procedure (protocol)

This subsection explains the contents of the data used in each control procedure.
1. Control codes
The table below shows control codes.
Signal name
STX
ETX
EOT
ENQ
ACK
1) When the PLC receives ENQ or ACK, it initializes the transfer sequence and begins receiving.
2) When the PLC receives EOT or CL as shown below, it initializes the transfer sequence.
At this time, the PLC gives no response.
For format 1
Computer side
PLC side
3) In FX , FX
3S
sending of the EOT/CL code from the computer to sending of the next message.
2. Station number
The station number indicates a number provided in each PLC to determine to which PLC the computer
accesses.
The station number is specified in hexadecimal.
• In FX Series PLCs, set the station number using parameters. The setting range is from 00H to 0FH.
• For the station number setting method in A Series PLCs, refer to the respective A Series PLC manual.
Computer
485PC-IF
In FX (FX), FX
2
M8002
Initial pulse
Cautions on setting station numbers
1) Do not overlap station numbers. If the same number is set for two or more stations, the transfer data is
destroyed and normal communication is not possible.
2) It is not necessary to set consecutive station numbers as shown in the setting example above. Any station
numbers in the setting range (00H to 0FH) are applicable.
(Examples: Station numbers may be set arbitrarily. Some station numbers may be skipped.)
D-50
Code Description
02H Start of Text
03H End of Text
04H End of Transmission
05H Enquiry
06H Acknowledge
E
O
T
or
C
L
Computer side
PLC side
, FX , FX and FX
3G 3GC 3U
FX
Series
 485 ADP
Station No. 0 Station No. 1
(00H)
and FX PLCs, set a value to D8121.
2C 0N
MOV H0 D8121
Signal name
LF
CL
CR
NAK
For format 4
E C L
O
T R F
or
C
C L
L R F
PLCs, a waiting time of 2 scan times or more is required from
3UC
FX FX
Series Series
 485 ADP  485 ADP
Station No. 2
(01H) (02H)
For details on the program, refer to Section 9.3.
6 Control Procedures and Setting Methods
6.4 Basic Formats of Dedicated Protocol
Code Description
0AH Line Feed
0CH Clear
0DH Carriage Return
15H Negative Acknowledge
FX
Series
 485 ADP
Station No. 15
(0FH)