Allen-Bradley 1770-LDA Operation manual

Line Driver/Receiver
Product Data
2
Your line driver/receiver consists of:
a two-slot chassis with two integral 1770-P1 power supplies
two Line Driver Receiver Modules (cat. no. 1772-DR)
two Connectors (cat. no. 1770-XE)
Figure 1
T wo slot chassis assembly
The two-slot chassis assembly (figure 1) consists of:
card guides, card edge connectors, and locking tabs to support two line
driver/receiver modules
two integral power supplies
a terminal strip for connection of incoming 120 or 220/240V fused AC
power
a circuit breaker that also acts as a power switch to allow removal and
installation of line driver/receiver modules
Figure 2shows chassis mounting dimensions.
The line driver/receiver modules provide the isolation, signal
amplification, and waveform squaring necessary to maintain satisfactory
signal levels over a 5000 foot cable length (figure 3).

Line Driver/Receiver
Product Data
3
Figure 2
Line Driver/Receiver chassis mounting dimensions
Figure 3
Line Driver/Receiver module

Line Driver/Receiver
Product Data
4
The line driver/receiver module is a plug-in module that mounts in one slot
of the two-slot chassis. Card guides on the top and bottom of the rack and
locking tabs at the front hold the module securely. The module’s edge
connector receives DC operating voltage from an integral power supply.
Two 15-pin connectors are mounted on the front of each module, one male
and one female. Two I/O Interconnect Cables (cat. no. 1778CR) or Belden
8723, connect the A (male) connectors of the four required modules (figure
4). One 1770-CW1 cable connects the PLC-2 family processor with the B
(female) connectors on the modules at one end of the link. A 1770-CW2
cable connects the B (female) connectors on the modules at the other end
of the link with the industrial terminal.
A red LED indicator is mounted on the module front plate and lights when
you connect the first line driver/receiver module to the second line
driver/receiver module.
Figure 4
Cabling for dual full duplex configuration

Line Driver/Receiver
Product Data
5
Dual full duplex configuration uses four line driver/receiver modules and
two chassis (figure 4). One data link handles communications while the
other provides handshaking for communications integrity.
Allen-Bradley recommends dual full duplex configuration to ensure
communication integrity between the PLC-2 family processor and the
industrial terminal. Communication integrity is essential if forcing
functions are entered through the industrial terminal and are not cleared
from the terminal before it is turned off. They will remain active until the
line driver/receiver power supply is de-energized.
You will need the following items to install a dual full duplex data link
(figure 4).
Two line driver/receivers, each consisting of:
- one two-slot chassis with two integral 1770-P1 power supplies
- two 1772-DR modules
- two 15-pin, female, D-shell, solder-cup 1770-XE connectors
Two I/O interconnect cables (cat. no. 1778-CR) or Belden 8723, 5000
feet maximum length
Two cables (cat. no. 1770-CW1 and cat. no. 1770-CW2) with three
15-pin, male, D-shell connectors with straight connector hoods (figure
5)
Figure 5
1770CW1 (left) and 1770CW2 cables for connecting the chassis with a
processor and an industrial terminal
Dual Full Duplex
Configuration
Material Required

Line Driver/Receiver
Product Data
6
Figure 6
Mounting detail
WARNING: Do not apply power to the power supplies until
after the installation is complete and checked. When installation
is complete and checked, apply power to the power supplies
only in accordance with the power-up procedure given in the
section following this installation procedure. Failure to observe
this warning might result in injury to personnel and damage to
equipment.
Figure 2shows your chassis mounting dimensions. The chassis must be
mounted within 10 feet of your processor and industrial terminal (figure 4).
Mount the chassis as follows:
Step 1 – Mount the chassis in a horizontal position on a surface that is
connected to an earth ground. You must have bare metal contact to ensure
good electrical contact between the chassis and the mounting surface.
Remove paint or other non-conductive finishes from the mounting surface
at the point of contact with the chassis mounting bolts (figure 6).
Step 2 – Place keying bands between pins 3 and 4, 9 and 10 on each line
driver/receiver module’s slot connector.
Step 3 – Position the module with the male socket on top and insert the
module into the slot.
Step 4 – Seat each module firmly in its connector by applying even
pressure to the edge of the module.
Step 5 – Lock the module in place with the locking tabs.
Complete the following steps before connecting AC line power to the
chassis.
Chassis and Line
Driver/Receiver Module
Driver/Receiver Module
Installation
Connections

Line Driver/Receiver
Product Data
7
Step 1 – Position jumper for appropriate AC input voltage (120V or
220/240V AC).
Step 2 – Connect AC input lines to terminals L1 and L2.
Step 3 – Connect equipment grounding conductor to ground terminal.
Step 4 – Connect the PLC-2 family processor to the two line drivers B
(female) connectors using a 1770-CW1 interconnect cable. Attach cables
so that stress is relieved at the connector hoods. Refer to figure 7.
Figure 7
1770CW1 cable wiring for connecting the processor to the 1770LDA

Line Driver/Receiver
Product Data
8
Step 5 – Connect the industrial terminal Channel A PLC-2 family
connector to the two line drivers B (female) connectors using a 1770-CW2
interconnect cable. Attach cables so that stress is relieved at the connector
hoods. Refer to figure 8.
Figure 8
1770CW2 cable wiring for connecting the industrial terminal to the
1770LDA

Line Driver/Receiver
Product Data
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Step 6 – Connect the line drivers, A (male) connectors using two 1778-CR
I/O interconnect cables or Belden 8723 (maximum length 5000 feet) and
four, 15-pin 1770-XE connectors. Refer to figures 4and 9.
Step 7 – Check all cable wiring against the above steps and figures 4, 7, 8,
and 9.
Figure 9
Remote I/O interconnect cable (Cat. No. 1778CR) and connectors
(Cat. No. 1770XE) for connection of line driver receiver modules

Line Driver/Receiver
Product Data
10
After you complete and check the two data link installations, apply power
to the system by performing the following steps. This sequence is
necessary to properly establish communication between the processor and
industrial terminal.
Step 1 – Energize the two line driver/receiver power supplies associated
with the PLC-2 family processor.
Step 2 – Energize the two line driver/receiver power supplies associated
with the industrial terminal.
Step 3 – Energize the industrial terminal.
Power has now been applied and communication between the PLC-2
family processor and the industrial terminal has been established.
Remove power from the system by performing the following steps in the
order given:
Step 1 – De-energize the industrial terminal.
You can perform steps 2 and 3 simultaneously.
Step 2 – De-energize the two line driver/receiver power supplies
associated with the industrial terminal.
Step 3 – De-energize the two line driver/receiver power supplies
associated with the PLC-2 family processor.
Figures 4, 7, 8and 9provide hardware information required to
troubleshoot the data link. Replaceable parts are listed under “Materials
Required.”
Analyze any installation and down-time troubles using the following check
list:
1. Check that wiring agrees with figures 7, 8, and 9.
2. Check that 1770-CW1 and 1770-CW2 cables are connected to the
correct modules at both ends of the link.
3. Check that all line driver/receiver modules are firmly seated in their
receptacles.
4. Check that all cable connectors are firmly seated.
5. Check that power supplies are receiving primary input power.
PowerUp
Power Shutdown
Troubleshooting