121
Wiring CP1H CPU Units
Section 3-4
• The circuit below should not be used for I/O devices with a voltage output.
Precautions when
Connecting a Two-wire DC
Sensor
When using a two-wire sensor with a 24-V DC input device, check that the fol-
lowing conditions have been met. Failure to meet these conditions may result
in operating errors.
1,2,3...
1.
Relation between voltage when the PLC is ON and the sensor residual
voltage:
V
ON
≤
V
CC
−
V
R
2.
Relation between current when the PLC is ON and sensor control output
(load current):
I
OUT
(min)
≤
I
ON
≤
I
OUT
(max)
I
ON
= (V
CC
−
V
R
−
1.5 [PLC internal residual voltage]*)/R
IN
When I
ON
is smaller than I
OUT
(min), connect a bleeder resistor R. The
bleeder resistor constant can be calculated as follows:
R
≤
(V
CC
−
V
R
)/(I
OUT
(min)
−
I
ON
)
Power W
≥
(V
CC
−
V
R
)
2
/R
×
4 [allowable margin]
3.
Relation between current when the PLC is OFF and sensor leakage cur-
rent:
I
OFF
≥
I
leak
Connect a bleeder resistor if I
leak
is greater than I
OFF
. Use the following
equation to calculate the bleeder resistance constant.
R
≤
R
IN
×
V
OFF
/(I
leak
×
R
IN
−
V
OFF
)
Power W
≥
(V
CC
−
V
R
)
2
/R
×
4 (allowable margin)
Vcc: Power voltage
Vr: Sensor output residual current
Von: PLC ON voltage
Iout: Sensor control output (load current)
Voff: PLC OFF voltage
Ion: PLC ON current
Ileak: Sensor leakage current
Ioff: PLC OFF current
R: Bleeder resistance
Rin: PLC input impedance
4.
Precautions on Sensor Inrush Current
An incorrect input may occur due to sensor inrush current if a sensor is
turned ON after the PLC has started up to the point where inputs are pos-
sible. Determine the time required for sensor operation to stabilize after the
sensor is turned ON and take appropriate measures, such as inserting into
the program a timer delay after turning ON the sensor.
IN
CP1H
0 V
+
COM
−
Output
Sensor
power supply
R
V
R
V
CC
R
IN
Two-wire Sensor
DC Input Unit
Содержание CP1H CPU UNITS - PROGRAMMING 05-2007
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Страница 3: ...CP1H X40D CP1H XA40D CP1H Y20DT D CP1H CPU Unit Operation Manual Revised March 2009...
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Страница 34: ...xxxiv Conformance to EC Directives 6...
Страница 174: ...140 CP series Expansion I O Unit Wiring Section 3 6...
Страница 370: ...336 Analog I O XA CPU Units Section 5 5...
Страница 552: ...518 Trouble Shooting Section 8 7...
Страница 595: ...561 Sample Application Section 9 12 Network Settings Network Tab Network Settings Driver Tab...
Страница 598: ...564 Sample Application Section 9 12...
Страница 642: ...608 Standard Models Appendix A...
Страница 643: ...609 Appendix B Dimensions Diagrams X XA and Y CPU Units 90 100 110 140 150 8 85 Four 4 5 dia holes...
Страница 652: ...618 Dimensions Diagrams Appendix B...
Страница 745: ...711 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Страница 746: ...712 Connections to Serial Communications Option Boards Appendix F...
Страница 776: ...742 PLC Setup Appendix G...
Страница 778: ...744 Specifications for External Power Supply Expansion Appendix H...
Страница 786: ...752 Revision History...