Yokogawa Data Acquisition with PID Control CX2000 - Manual (Page 135)

2-18
IM 04L31A01-01E
When using the reference junction compensation of the CX2000 through thermocouple
input, take measures to stabilize the temperature at the terminal section.
• Always attach the terminal cover.
• Do not use thick wires with high heat radiations effects (cross-sectional area of 0.5
mm 2 or smaller recommended).
• Keep the ambient temperature consistent. Large temperature fluctuations can occur
as a result of such things as turning ON/OFF a nearby fan.
To protect the control current output/voltage pulse output section from external
noise such as electrical serges, it is recommended that an external serge
protector (such as AR-SA (for current output) or AR-LP (for volrage pulse output)
by Yokogawa M&C Corporation) be connected.
Connecting the input wires in parallel with other instruments may mutually affect
the measured values. If you need to make a parallel connection:
• Turn OFF burnout.
• Ground each instrument at a single common point.
• Do not turn ON/OFF the instrument during operation. It may cause adverse affects on
other instruments.
• Resistance temperature detectors cannot be connected in parallel.
Wiring Procedure
1. Turn OFF the power to the CX2000 and remove the terminal cover.
2. Wire the signal wires to the terminals.
3. Attach the terminal cover and secure it with screws.
Measurement Input Wiring
DC voltage input, DI (ON/OFF) input
• Thermocouple input
• DC voltage input, DI (ON/OFF) input
• RTD input
• DC current input
DC current input
Shunt resistor
Example: For 4 to 20 mA input,
shut resistance values should be
250 Ω ±0.1%.
–
+
Lead wire resistance
per wire of 10 Ω or less.
Make the resistance of
the three wires equal.
A
b
B
Compensation lead
b
A
B
b
A
B
b
A
B
b
A
B –
+
Note
On the standard measurement input block, RTD input terminals A and B are isolated on each
channel. Terminal b is shorted internally across all channels. If you specified the three-wire
isolated RTD (/N2) option, b terminals are isolated with each other.
2.3 Wiring