Circuit
FG (Grounding Terminal)
7
7
1
1
SG
FG
J1
SG
FG
AKB136 cable
D-sub25 side
Protective grounding system
Figure 5.5.1-7 Example of Using AKB136 Cable
If the external device is insulating the RS-232C communication circuit, communication circuits
at both the ALR111 and external device are floating, and thereby lowering noise resistance
severely.
To prevent this, use an AKB131 or AKB132 cable.
Connect pin No. 1 (for the frame ground) and pin No. 7 (for the signal ground) together at the
external device side. In addition, as a means of grounding the shielding wires of this cable,
the following figure shows that the shielding wires can be connected to the FG terminal at the
external device in cases where pin No. 1 is floating (open) at the external device.
Circuit
FG (Grounding terminal)
FG
7
1
SG
SG
FG
Open
AKB131 cable or
AKB132 cable
To FG of
the cable
To a protective
grounding system
(two ring terminals
may be connected
to each other.)
7
1
D-sub25 side
Protective grounding system
Figure 5.5.1-8 Cable Connection for Insulated Communications Circuit
n
Connection to External Device
The ALR111 and external device are connected by a cable up to 15 meters in length.
If the ALR111 is directly connected to an external device, be sure to connect the FG at the
external device to the protective grounding system.
If the cable is longer than 15 meters, always use a modem. Be sure to ground the FG of the
modem to the protective grounding system.
<5.5 Connection of Communication Modules >
5-40
IM 32Q06C10-31E
4th Edition : Jan.30,2015-00
