Wiring - Mitsubishi Electric MELSEC-L02SCPU User Manual

Cpu module, built-in i/o function
Table of Contents

Advertisement

8.2.2

Wiring

This section describes wiring to an encoder and a controller. For connectors used for external wiring, refer to the 
MELSEC-L CPU Module User's Manual (Hardware Design, Maintenance and Inspection).
(1) Wiring precautions
• Inputting a signal with a different voltage may cause malfunction of the module and failure of the connected
devices.
• In 1-phase input, connect a pulse input cable to A-phase line.
• When inputting high-speed pulses, take the following noise reduction measures.
• Always use a shielded twisted pair cable and ground the FG and LG terminals to the protective ground
conductor dedicated to the programmable controller.
• To prevent noise from power cables and I/O cables, do not install shielded twisted pair cables in parallel
with them and separate the shielded twisted pair cables at least 100mm away from them. Also, wire the
shielded twisted pair cables with the shortest distance. The following figures show an example of noise
reduction measures.
Inverter
Terminal
block
Install these cables at least
100mm away from the I/O
cables of high voltage
equipment such as a
relay and an inverter.
(Apply this wiring in a control
panel as well.)
AC motor
• Ground the shielded twisted pair cable on the encoder side (relay box). (This example shows wiring using
24V sink type.)
Current for the encoder
To
A
To
B
To LCPU
(2) Connectable encoders
Check that the output voltages of the following encoders meet the specifications of the high-speed counter
function ( Page 238, Section 8.9).
• Open collector output type encoder
• Line driver output type encoder
LCPU
Terminal block
Avoid using a solenoid valve and inductive load together in the same metallic pipe.
If a sufficient distance cannot be secured with a high voltage cable in wiring in a duct,
use a CVVS type shield wire or other shield wires for the high voltage cable.
Cart
+24V
To the encoder
0V
A
B
24V
E
E
CHAPTER 8 HIGH-SPEED COUNTER FUNCTION
Relay box
Wire the encoder and the relay box with the shortest distance.
If the distance between the LCPU and the encoder is long,
a voltage drop may occur.
Therefore, check that voltages while the encoder is in operation
and in stop are within the rated voltage of the encoder at the
terminal block of the relay box using a measure such as a
synchronoscope.
Encoder
Connect the shield wire of the encoder and the shield wire of the
shielded twisted pair cable at inside of the relay box.
If the shield wire of the encoder is not grounded inside the encoder,
ground the wire in the relay box as indicated by the dotted line.
8
185

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents