How To Connect The Rs-232 Interface - Mitsubishi Electric QJ71MB91 User Manual

6
PRE-OPERATIONAL PROCEDURES AND SETTINGS

6.5.1 How to connect the RS-232 interface

This section describes connection precautions and a connection example for using the
QJ71MB91 RS-232 interface.
(1) Connection precautions
(a) Connection cable's FG signal line and shield
(b) Connection diagram
Connect the connection cable's FG signal line and shield as follows:
Table6.5 Connection cable's FG signal line and shield
Item Connection on the QJ71MB91 side
Connection Connect to the QJ71MB91 side connector
cable's FG signal housing.
Connecting Connect to the target device's FG terminal or
cable's shield the QJ71MB91 side connector housing.
Connect the lines as shown below.
1) Connect the FG terminal on the target device and the QJ71MB91 side using
the shield of the connection cable.
2) Connect each signal line other than SG with the SG signal line in twisted pair.
QJ71MB91 side
To connector
housing
SD
RD
Output for cable
disconnection
detection
Input for cable
disconnection
detection
SG
Shield
Figure 6.9 RS-232 cable shield
6.5 Connection to a Target Device
6.5.1 How to connect the RS-232 interface
Remarks
Do not short-circuit the FG and
SG signal lines of the
connection cable.
When the FG and SG signal
lines are connected inside the
target device, do not connect
the FG signal line to the
QJ71MB91 side.
Target device side
FG
RD
SD
SG
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