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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 - 05-2006
Страница 1: ...OPERATION MANUAL CP1H CPU Unit SYSMAC CP Series CP1H X40D CP1H XA40D CP1H Y20DT D Cat No W450 E1 02...
Страница 2: ...CP1H X40D CP1H XA40D CP1H Y20DT D CP1H CPU Unit Operation Manual Revised May 2006...
Страница 3: ...iv...
Страница 11: ...xii TABLE OF CONTENTS...
Страница 15: ...xvi...
Страница 19: ...xx...
Страница 31: ...xxxii Conformance to EC Directives 6...
Страница 71: ...40 Function Blocks Section 1 5...
Страница 133: ...102 Computing the Cycle Time Section 2 7...
Страница 169: ...138 CPM1A Expansion I O Unit Wiring Section 3 6...
Страница 411: ...380 Clock Section 6 8...
Страница 519: ...488 Replacing User serviceable Parts Section 10 2...
Страница 527: ...496 Standard Models Appendix A...
Страница 535: ...504 Dimensions Diagrams Appendix B...
Страница 628: ...597 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Страница 629: ...598 Connections to Serial Communications Option Boards Appendix F...
Страница 659: ...628 PLC Setup Appendix G...
Страница 665: ...634 Index work words 159 write protection 370...
Страница 667: ...636 Revision History...