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Yokogawa Data Acquisition with PID Control CX2000 User Manual

Page 240

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9-7

IM 04L31A01-17E

9

Green Series Communications

Executing Auto Reading

• When the connecting model is UT Series

Various setup information can be automatically read from the connected
device. If you specify the [Modbus address] on the External loop setting (Basic
setting) display and execute [Auto reading], the CX, which is set to be the
Modbus master, reads the following setup information from the connected
device automatically.
1.

Type of instrument connected.

2.

Decimal point position and unit of PV, SP, and OUT values.

3.

High and low limits of the control span.

4.

Control mode (single loop control, cascade control, etc.). Referred to as
the UT mode on the UT series.

5.

Control output type

6.

Alarm type

The setup information can also be entered using the operation keys.

Based on the setup information that is automatically read, [Parameter address
setting] and [Tuning setting] are also automatically set.

Even if the instrument connected is of the UT series, if using “heating/cooling
control” or “custom computation control,” ETC is set for the connection type.

• When the connecting model is “ETC”

Auto reading cannot be performed. You can only enter the items of 1 and 2 above
using the operation keys.

Setting (Correcting) the Read Data

If the data is not read correctly using the auto reading function, the following items can
be entered (corrected) using the operation keys.
• Decimal point position of PV (process value), SP (setpoint), and OUT (control

output).
You can set the decimal point position in the range of 0 to 4.

No decimal point when set to 0.

One digit to the right of the decimal when set to 1.

Two digits to the right of the decimal when set to 2.

Three digits to the right of the decimal when set to 3.

Four digits to the right of the decimal when set to 4.

• Unit of PV (process value), SP (setpoint), and OUT (control output).

Set the unit using up to 6 alphanumeric characters.

• High and Low Limits of the Control Span

Set the limits in the range of –30000 to 30000.

The decimal point position of PV above is used. For example, if the decimal
point position is set to “1” and you enter “10000,” it is taken to be “1000.0”.

9.4 External Loop Setting > Basic Setting