Yokogawa Button Operated MV2000 - Manual (Page 71)

3-13 M-4662
Using
the
Serial
Interface
1
2
3
4
5
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7
App
Index
3.6 Usage Example of the Modbus Function
This section explains an example of setting two MV1000s that are connected via the
serial interface, one configured to be a Modbus master and another configured to be a
Modbus slave. This section refers to the RD-MV1000 configured to be a Modbus master
as the RD-MV1000 master and the RD-MV1000 configured to be a Modbus slave as the
RD-MV1000 slave.
System Configuration and Operation
The measurement channels, computation channels, and communication input data
shown below will be used. We assume that the serial interface is already configured.
MV1000 slave
(Modbus slave)
Serial
communication
Reads measured data from the MV1000 and
displays data on a computation channel
(/M1 or /PM1 option).
MV1000 master
(Modbus master)
Measurement channel 1
Input range: –2.0000 to 2.0000 V
Computation channel 101
–2.0000 to 2.0000 V
Communication input data C01
Address: 1 Address: 2
Start the computation
Displayed in group 1
Measured data
Command
Operation
• The RD-MV1000 master reads the measured value from the RD-MV1000 slave
channel 1 into communication input channel C01 and displays the value on
computation channel 101. The MV displays computation channel 101 in group 1.
• The measured value of RD-MV1000 slave channel 1 is transferred to the RD-MV1000
master as an integer in the range of –20000 to 20000.
• The RD-MV1000 master displays values in the range of –2.0000 to 2.0000 V for
values in the range of –20000 to 20000. The value is linearly scaled using the
following equation.
The value on RD-MV1000 master computation channel 101 = Communication input
data C01 Ч 0.0001