Ac Input Units; Precautions When Connecting A Two-Wire Dc Sensor - Omron CJ2 CPU UNIT User Manual

Cj2 cpu unit hardware
Hide thumbs Also See for CJ2 CPU UNIT:
Table of Contents

Advertisement

5 Installation

AC Input Units

Contact output
AC Switching
Proximity
switch
main
circuit
Precautions for Safe Use
When using a reed switch as the input contact for an AC Input Unit, use a switch with an allow-
able current of 1 A or greater. If reed switches with smaller allowable currents are used, the con-
tacts may fuse due to surge currents.

Precautions when Connecting a Two-wire DC Sensor

When using a two-wire sensor with a 12-VDC or 24-VDC input device, check that the following con-
ditions have been met. Failure to meet these conditions may result in operating errors.
• Relation between voltage when the PLC is ON and the sensor residual voltage:
≤ V
V
ON
CC
• Relation between voltage when the PLC is ON and sensor control output (load current):
(min) ≤ I
I
OUT
I
= (V
ON
CC
When I
ON
can be calculated as follows:
R ≤ (V
− V
CC
Power W ≥ (V
V
: Power voltage
CC
V
: Sensor output residual current
R
I
: PLC ON current
ON
I
: Sensor control current (load current)
OUT
R
: PLC input impedance
IN
5-36
IN
AC Input Unit
COM
IN
AC Input Unit
COM
− V
R
≤ I
(max.)
ON
OUT
− V
− 1.5 [PLC internal residual voltage])/R
R
is smaller than I
(min), connect a bleeder resistor R. The bleeder resistor constant
OUT
(min.) − I
)/(I
)
R
OUT
ON
− V
/R × 4 [allowable margin]
2
)
CC
R
IN
CJ2 CPU Unit Hardware User's Manual

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents