Mitsubishi Electric FX3U-ENET-ADP, Руководство пользователя

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7 Communication Using MC Protocol
54
FX
3U
-ENET-ADP User's Manual
7.3 Message Formats and Control Procedures
7.3.3 Contents of data designation items
This section explains the data items of commands and responses when communicating using MC protocol.
In the response that is returned by the Ethernet adapter to an external device, the data is automatically
specified by the Ethernet adapter; the user does not need to specify it.
1) Header
The header for TCP/IP or UDP/IP is used. The user does not need to specify it at the PLC side; the
Ethernet adapter attaches it.
2) Subheader
The format of the subheader is configured as follows.
3) PC number
The PC number is fixed at a value of "FFH".
a) When communicating in binary code, the PC number is expressed in binary value.
b) When communicating in ASCII code, the PC number is expressed in hexadecimal ASCII code.
4) Monitoring timer
This is a timer for setting the period of time that the Ethernet adapter should wait after outputting a read/
write request to the PLC until the result is returned.
a) Specify the value as shown below.
0000H (0) : Waits infinitely
(It keeps waiting until a response is returned from the PLC.)
0001 to FFFFH (1 to 65535) : Wait time (in units of 250 ms)
b) For normal data communications, using a value within the setting range of 1 to 40 (0.25 to 10s) is
recommended.
5) Character area (command)
This data contains the Ethernet adapter commands that indicate functions for when an external device
reads/writes data from/to the target PLC station.
The contents and order of data in the character area (command) field differ depending on the function
used.
The order of data items for each function is explained in each function's reference section in Subsection
7.5.2 and later.
6) Character area (response)
This data contains data read/processing result when an external device reads/writes data from/to the
target PLC station.
The contents and order of data in the character area (response) differ depending on the function used.
The order of data items at normal completion for each function is explained in each function's reference
section in Subsection 7.5.2 and later.
Command/response type
(This differs for each function. For details,
refer to Section 7.4 and later.)
Command/response flag
For command: 0
For response: 1
B7 B6 B5 B4 B3 B2 B1 B0