TUNNEL MASTER JR MANUAL
System Hardware
18
The Relay Box Jumper Settings
Jumper Settings
The following picture and table will explain the location and
purpose of the various jumpers on the Relay Box circuit board.
The following picture shows the Relay Box door circuit board and
location of the various jumpers, switches and controls.
Relay Box Circuit
Board
Jumper Function
These are the jumper functions and their settings
Jumper Setting
Function
J1 N/A
Does not exist
J2 ON
BIAS High (+) set ON for the Main Relay box only.
J3 485
3 position jumper should be on 2 pins to select 485 Communication
(UP)
J4 485
3 position jumper should be on 2 pins to select 485 Communication
(UP)
J5 ON
Transmit terminating resister. Only ON if first or last device in
network.
If you have a 24-output system this should be ON. IF you have a
48-output system, the main relay box should be OFF and the second
relay box should be ON.
JP4
JP10
JP6
JP7
JP5
JP2
JP3
JP8
JP9
JP11
Dip Switch
Contrast Control
for front of box
LED display
(SW1) Circuit
Board Reset
Button