2.7 Communications with a Mitsubishi PLC (QnA-compatible 3E Frame Protocol)
Message Functions
2-184
M Register Writing Range (PARAM36 to PARAM39)
These parameters set the allowable address range for write requests from the remote station. An error will
occur if the write request is outside this allowable range.
Specify the M Register Writing Range (PARAM36 to PARAM39) with word addresses.
Note: 1. M registers are always used as the destination in the MP3000 for data write requests from the remote station.
2. The writing range parameters allow you to specify the range of M registers that messages are allowed to write to.
The following table lists the writing range parameters.
Set the writing range so that it satisfies the following condition:
0 ≤ M register writing range LO ≤ M register writing range HI ≤ Maximum M register address
The writing range applies when using the following function codes.
0B hex: Writes to hold registers (extended).
0F hex: Changes the states of multiple coils.
10 hex: Writes to multiple hold registers.
G Register Writing Range LO (PARAM40 and PARAM41)
This parameter is not used for the QnA-compatible 3E Frame protocol.
G Register Writing Range HI (PARAM42 and PARAM43)
This parameter is not used for the QnA-compatible 3E Frame protocol.
O Register Writing Range LO (PARAM44 and PARAM45)
This parameter is not used for the QnA-compatible 3E Frame protocol.
O Register Writing Range HI (PARAM46 and PARAM47)
This parameter is not used for the QnA-compatible 3E Frame protocol.
Parameters Meaning Description
PARAM36 and
PARAM37
M Register Writing Range LO First address of the writing range
PARAM38 and
PARAM39
M Register Writing Range HI Last address of the writing range
Use the following settings to set the allowable writing range of M register addresses to
MW0001000 to MW0001999:
PARAM36 = 03E8 hex (1000)
PARAM37 = 0000 hex (0000)
PARAM38 = 07CF hex(1999)
PARAM39 = 0000 hex (0000)
The MP3000 will return an error if a write request is received for an address outside the range from
MW01000 to MW01999, and will not perform the writing operation.
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