MJ-X Communications Module
7
Table 3-1 Fiber Optic Version Jumper Settings
Jumper
Name
Position Function Selected
State Description
1-2
Auto Repeat
Auto repeat for mark 0 or mark 1
2-3
No Repeat
Force 0
J14 Auto
Repeat
Out
No Repeat
Force 1 (no jumper installed at 1-2 or 2-3)
Out
Normal
Set Low Power Transmitter Output
J12 Range
In
Long
Set High Power Transmitter Output (See Note 2)
Note 1:
Default pin settings are shown in bold text.
Note 2:
If 50/125
µ
m cable is used, J12 must be jumpered (In). See section 5.1 for details.
3.1.2 RS-232/485
Version
Figure 3-2 shows the jumper locations on the RS-232/485 version, viewed from the component side. Jumpers and
their default settings are listed in Table 3-2.
In an RS-485 application, connect Signal Return (RTN) between the communication devices when there is a ground
potential rise between the connected devices. When the device RTN pins are connected, jumper J11 should be
disconnected (unless required by safety codes) to prevent ground loop currents.
Table 3-2 RS-232/485 Board Jumper Settings
Jumper
Name
Position Function Selected
State Description
1-2
Receive Enable
RS-485 receiver is always enabled
J10 RS-485
RCV EN
2-3
Auto Enable
RS-485 receiver is automatically enabled by MJ-X
Communication Module microprocessor control.
Out
Not grounded
Signal Return not connected to frame ground
J11 Safety
Ground Strap
In
Grounded
Signal Return connected to frame ground
Note:
Default pin settings are shown in bold text.
Содержание MJ-X Series
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