Yokogawa Value Series FX1000 - Manual (Page 79)

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IM 04L21B01-17EN
Using the Serial Communication Interface (/C2 and /C3 Options)
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App
Index
2.7 Usage Example of the Modbus Function
Explains the setting example for both Modbus master and slave on FX1000s connected
via the serial communication.
In this section, the FX that has been set as the Modbus
master is referred to as “FX1000 master.” FXs that have been set as Modbus slaves are
each referred to as “FX1000 slave.”
System Configuration and Actions
Uses the measurement channel, computation channel, and communication input data as
described in the figure below. Assumes other conditions are set properly.
FX1000 slave
(Modbus slave)
Serial communication
Reads the FX1000’s measured data,
and uses a computation channel
(/M1, /PM1, and /PWR1 options) to display it.
FX1000 master
( Modbus master)
Measurement channel 001
Input range: –2.0000 to 2.0000 V
Computation channel 101
-2.0000 to 2.0000V
Communication input data C01
Address: 1
Start the computation
Display the channel on Group 1
Measured data
Command
Action
• The FX1000 master reads the measured value of channel 001 on the FX1000 slave
into the communication input data C01. C01 is displayed on a computation channel
101 by including the data in the equation. The computation channel 101 is assigned to
Group1.
• The measured value of channel 001 on the FX1000 slave is transferred to the FX1000
master as an integer in the range of –20000 to 20000.
• The FX1000 master displays the read data as –2.0000 to 2.0000 V on the
computation channel 101. The following conversion is applied.
Value on the computation channel 101 of the FX master
= Communication input data C01 x 0.0001