22
YORK INTERNATIONAL
FORM 450.20-N20 (702)
INSTALLATION
Termination
The RS485 standard requires that a terminator reside
at the end of each network. This helps to balance the
two signal lines and prevents signal reflection back
onto the transmission lines.
Termination is required at the end of each network.
When repeaters are used to extend the network,
termination is required at the end of each segment.
Since the Universal LINC485 does not have a 5 VDC
power terminal on Port 2, a small, 24 AWG wire
approximately 6 in. (150 mm) long can connect
between the 5 VDC terminal on Port 1 to the
unlabelled terminal on Port 2. Terminator modules
(Part No. 031-01488-000) can then be installed at
each port on the Universal LINC485.
Switch Settings
In order to provide a simple but flexible product, the
Universal LINC485 uses a bank of DIP switches to
configure the devices. As the DIP switches are
positioned, the software makes adjustments to ensure
proper operation for the selected functions.
NOTE: The wire connections and
selected switch settings must match for
the devices to function properly.
There are 12 DIP switches on the Universal
LINC485. They are labelled according to function;
Device Type, Device Baud Rate or Mode, Node
Address, and Communication Rate.
The Universal LINC485 does not use all the switches
available in each category.
Device Type
The available device types are:
Repeater
Router
To select the device use switch S1. Set the switch to
OFF to operate as a router. Set the switch to ON to
operate as a repeater. The DIP switch labelled 2 is not
used.
When the device type is changed, the STATUS LED
flashes once to indicate the change.
Mode
The operation of the Mode switch is dependent on the
location within the network. The Mode switch
enables a network filter that fragments the LAN for
more efficient data transmission. It prevents unneces-
sary data transmission throught the Universal
LINC485 when operating as a repeater at 50 kbaud.
When installed on a 19.2 kbaud network as a re-
peater, the Universal LINC485 operates as a “dumb”
repeater, transferring any message recieved at one
port out the other port. When installed on a 50 kbaud
network as a repeater, it becomes a “smart” repeater,
transferring only certain messages. The messages
which are transferred can be selected by the position
of the Mode switch.
NOTE: The Mode switch is only effec-
tive on 50 kbaud (Rev 77 and later)
networks when operating as a repeater.
The CS switch must be set to ON and
S1 must be ON. If either of these
switches are OFF, the Mode switch has
no effect and all messages are trans-
ferred across the entire network.
Figure 9. Terminator Module Power
UNIVERSAL
LINC485
TX
RX
TX
RX
SCREEN
P3
P2
GND
5VDC
GND
P2
P3
USHL
LAN
PORT 2
LAN
PORT 1
STATUS
S1
MODE
1
2
4
8
16
32
64
CS
OFF ON
24 AWG Wire
S1 LINC
OFF ROUTER
ON REPEATER
MODE SWITCH IS
FOR 50K REPEATER
ONLY. SEE MANUAL
CS OFF 19K2 LAN
CS ON 50K LAN
5VDC
