Settings - Omron CQM1H series Operation Manual

Settings

3-1 Settings
3-1-1 Wiring
Voltage Input
Current Input
3-1-2 Wiring Precautions
DC Relay
86
• Connect a two-conductor twisted-pair shielded cable to the Analog Input Unit.
• The input terminals of the Analog Input Unit, to which the two-conductor
twisted-pair shielded cable is connected, vary with the input range as shown in
the following illustrations. In some environments, the shielded wire of the two-
conductor twisted-pair cable should be connected to the COM terminal instead
of the FG terminal of the Analog Input Unit so that the Analog Input Unit will not
be influenced by external noise.
• The COM terminal is internally connected to the analog 0-V terminal of the
Analog Input Unit.
V+
V–
I+
COM
FG
FG
Short-circuit the V+ and I+ terminals for current input.
V+
V–
I+
COM
FG
FG
In order to prevent noise interference, note the following when wiring the Analog
Input Unit:
• Do not install power lines or high-tension lines along in close proximity to the
Analog Input Unit's input lines.
• When connecting an inductive load such as a relay, solenoid, or electromagnet
valve to the Analog Input Unit, be sure to insert a surge absorption diode or
surge absorber to the load circuit as shown in the following examples. The
surge absorption diode or surge absorber must be as close as possible to the
inductive load in the load circuit. The withstand voltage of the surge absorption
diode must be at least five times as large as the circuit voltage.
DC
Surge absorption diode (Fuji Den-
ki's ERB44-06 or equivalent)
Section 3-1
0 V
0 V