A-B 1747-SN Remote I/O Scanner

Overview

The Remote I/O (RIO) Scanner, 1747-SN, enables communication between an

SLC™ processor and remotely located 1746 I/O chassis and other RIO-compatible

Allen-Bradley operator interface and control devices. The 1747-SN scanner

communicates with remote devices using the A-B Remote I/O link. The RIO link

consists of a single master (scanner) and multiple slaves (adapters). Communication

between devices occurs over twisted-pair cable with the devices daisy-chained

together. Maximum distance for remote communication is 3,048m (10,000 ft.). The

scanner is compatible with any standard RIO adapter device.

The SLC processor transfers a maximum of 4 logical racks (32 input and 32 output

image words) of discrete remote I/O data into the SLC input and output image files.

You can adjust the size of the scanner image files during configuration of your SLC

system so that the scanner only transfers the discrete I/O data required by your

application program. The 1747-SN Series B or later RIO Scanner can be configured

to transfer up to 64 words of data to a remote device via block transfer. Refer to

publication 1747-6.6, Remote I/O Scanner User Manual, for information on

configuration, programming, and block transfers.

The SLC 500™ processor (SLC 5/02 or higher) supports multiple scanners in its local

I/O chassis. The maximum number is dependent on the following:

• backplane power requirements (power supply dependent)

• SLC 500 processor I/O data table limit (4,096 input and output bits)

• processor memory to support the application (SLC processor dependent)

Required Tools and Equipment

Have the following tools and equipment ready:

• medium blade screwdriver

• termination kit (the package, containing resistors and a ring lug, which was

included with the scanner)

• approximately 38 cm (15 inches) of #20 AWG wire for grounding the drain

shield to the SLC chassis (for Series A retrofits)

• adequate length of RIO communication cable (Belden™ 9463) for your

specific application

RIO Link Wiring

The scanner is connected to other devices on the RIO link in a daisy-chain (serial)

configuration. There are no restrictions governing the space between each device,

provided the maximum cable distance (Belden 9463) is not exceeded. A 1/2 watt

terminating resistor (included with the module) must be attached across line 1 and

line 2 of the connectors at each end (scanner and last physical device) of the RIO

link. The size of the resistor depends on the baud rate and extended node

capability, as shown in the table below.

Note: To use extended node, all devices on the RIO link must support it. Refer to

each device’s user manual.