Yokogawa Button Operated MV2000 - Manual (Page 162)

7-9 M-4662
Specifications
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App
Index
Hold Register (shared with the Modbus slave function)
• Common Items
• The client device can read and write to the hold registers.
• Communication input data is an option (/M1 or /PM1).
• External input channels are an RD-MV2000 option (/MC1).
To Write Data
• Communication input data can be handled on a computation channel by writing an
expression that contains the data in an MV computation channel.
• External input channel data can be handled on an external input channel.
• Details
Hold Register Data Data Type
40001 Communication input data C01 16-bit signed integer
| |
40060 Communication input channel C60
• Precautions to be taken when a client device reads data
The MV communication input data is in floating point format, but the data is converted to
16-bit signed integer when the data is read.
• Precautions to be taken when a client device writes data
A client device can only write data in 16-bit signed integer format. A client device cannot
write a floating point value.
40301 Lower word of communication input data C01 32-bit floating point
40302 Higher word of communication input data C01
| |
40419 Lower word of communication input data C60
40420 Higher word of communication input data C60
• Precautions to be taken when a client device writes data
Input range: –9.9999E29 to –1E–30, 0, 1E–30 to 9.9999E29
If values outside this range are used on a computation channel, a computation error
occurs.
41001 External input channel write register 201 16-bit signed integer
| |
41240 External input channel write register 440
• Precautions to be taken when a client device writes data
A client device can only write 16-bit signed integer data.
The measurement range and unit are set on the external input channels. The decimal
place is determined by the external input channel’s span lower settings.
Modbus Error Response (common to Modbus server and Modbus slave)
The MV returns the following error codes to a client or master device.
Code Function Operation
1 Bad function code Unsupported function request.
2 Bad register number Tried to read or write to a register that does not have a
corresponding channel.
3 Bad number of registers When writing: The specified number of registers is less than
or equal to zero or greater than or equal to 124.
When reading: The specified number of registers is less than
or equal to zero or greater than or equal to
126.
The MV does not return a response in the following cases.
• CRC error
• Errors other than those shown above.
7.3 Modbus Protocol Specifications