Pulse Catch (M8170 To M8175) - Mitsubishi Electric FX3S Quick Start Manual

FX3S QUICK START MANUAL
n INSTRUCTIONS FOR CONNECTING INPUT DEVICES
1. In the case of no-voltage contact:
The input current of this PLC is 7 mA/24 V DC. (5 mA/24 VDC in
X010 or later). Use input devices applicable to this minute current.
If no-voltage contacts (switches) for large current are used, contact
failure may occur.
Input Number
X000 to X007
X010 to X017
In the case of input device with built-in series diode:
The voltage drop of the series diode should be approx. 4 V or less.
When lead switches with a series LED are used, up to two switches
can be connected in series. Also make sure that the input current is
over the input-sensing level while the switches are ON.
In the case of input device with built-in parallel resistance:
Use a device having a parallel resistance, Rp, of 15 kΩ or more. If the
resistance is less than 15 kΩ, connect a bleeder resistance, Rb (kΩ),
obtained by the following formula as shown in the following figure.
4Rp
Rb (kΩ) ≤
15-Rp
In the case of 2-wire proximity switch:
Use a two-wire proximity switch whose leakage current, lr, is 1.5 mA
or less when the switch is off. When the current is larger than 1.5 mA,
connect a bleeder resistance, Rb (kΩ), determined by the following
formula:
6
Rb (k ) ≤
I -1.5

4.5 PULSE CATCH (M8170 TO M8175)

The PLC (main unit) is provided with a pulse catch function and has 6
pulse catch input points.
For details on programming, refer to the HELP menu in GX Works2.
n ALLOCATION OF SPECIAL MEMORIES TO INPUT NUMBERS
(ON DURATION OF INPUT SIGNALS)
Input Number Contact on Sequence Program
X000 M8170
X001 M8171
X002 M8172
X003 M8173
X004 M8174
X005 M8175
n CAUTIONS FOR PULSE CATCH
Non-overlap of input numbers: The input terminals X000 to X005
can be used for high-speed counter, input interruption, pulse catch,
SPD instruction, ZRN instruction, DSZR instruction and general-
purpose inputs. Take care not to overlap the input numbers.
Cautions in wiring: It is recommended to use shielded twisted-pair
cables for connection cables.
n EXAMPLES OF EXTERNAL WIRING
It is recommended to use shielded twisted-pair cables for connection
cables. Ground the shield of each shielded cable only on the PLC side.
10
Mitsubishi Electric Automation, Inc.
Input Current
7 mA/24 VDC
5 mA/24 VDC
ON Duration of Input Signal
10µs or more
50µs or more
n EXAMPLES OF PULSE CATCH (M8170) WIRING USING X000
When another input terminal is used, wire it according to the following
diagrams.
When 24VDC service power supply is used
Sink wiring
Fuse
L
Class D grounding *
N
S/S
0V
24V
X000
Source wiring
Fuse
L
Class D grounding *
N
S/S
0V
24V
X000
* The grounding resistance should be 100Ω or less.
When 24VDC external power supply is used
Sink wiring
Fuse
L
C a l s s D g o r u n d n i g *
N
S/S
0V
24V
X000
Source wiring
Fuse
L
C a l s s D g o r u n d n i g *
N
S/S
0V
24V
X000
* The grounding resistance should be 100
Three-wire
Three-
wire
24V DC
Three-wire
24V DC
Three-
wire
or less.