A-B 1785-L80B Enhanced PLC-5 Series Programmable Logic Controller

Description.

The 1785-L80B is an Allen-Bradley Enhanced PLC5 programmable logic controller (PLC).

The controller has 100.000 words of embedded user memory and is equipped with several communication interfaces.

Examples include four (4) DH/Remote I/O (adapters or scanners), one (1) configurable RS-232. -423. and RS-422A compatible serial port, and two (2) programming terminals.

It can accommodate up to 3072 arbitrary mixes or 3072 inputs and 3072 outputs in free mode!

About the 1785-L80B

The Programmable Controller 1785-L80B is the core component of every control system based on the Allen-Bradley PLC-5 Series.

The 1785-L80B connects local, expansion, and remote I/O modules on a variety of communication interfaces into a single control system.

There are four built-in ports on the 1785-L80B controller. The ports are labelled Channel 1A, Channel 1B, Channel 2A and Channel 2B.

All ports can be configured as remote I/O scanners, remote I/O adapters, and DH communication interfaces.

DH communications can be used both for remote programming and monitoring of the 1785-L80B and for creating peer-to-peer communication networks between various PLC-5 controllers.

The Remote I/O connection is used for real-time data exchange between the controller and I/O, operator interface and other functions.

All four channels on the 1785-L80B can be used as either remote I/O scanners or remote I/O communications adapters.

The Remote I/O Scanner mode reads and writes I/O information between the controller and remote I/O devices.

In this mode, the 1785-L80B is the supervisory controller for other controllers and remote I/O adapter modules that are in adapter mode.

When any of the four channels 1A, 1B, 2A, or 2B are operating in Remote I/O Adapter mode, the controller monitors the local I/O where its controllers reside.

It also communicates with the supervisory controller via the remote link. On the 1785-L80B, Data Highway+ (DH) links are available on all four available channels.

DH communications can be used to transmit data to other PLC-5 controllers or other advanced components of the control system.The DH link can be programmed to multiple PLC-5 controllers.

On the front panel of the 1785-L80B controller is a 25-pin connector labelled channel 0. This is an optically isolated EIA RS232C port.

Channel 0 supports ASCII and DF1 full-duplex and half-duplex master-slave protocols. There is a green channel 0 communication indicator on the front panel.

Next to channel 0. there are two 8-pin mini-DIN connectors labelled channel 1A and channel 2A, and a DH programming terminal connection parallel to channels 1A and 2A.

There are four three-pin connectors used as communication ports. These three-pin connectors are used for channels 1A, 1B, 2A, and 2B.

All of these ports can be used as Remote I/O Scanners, Remote I/O Adapters, or DH communication ports.The maximum cable length of the DH link depends on the transmission rate.

It is critical that all devices on the DH link communicate at the same rate. This length increases from a maximum of 3048 metres at 57.6 kilobits per second to 762 metres at 230.4 kilobits per second.

The 1785-L80B has multiple indicators on the front panel for easy interaction. The indicators show various controller statuses. The indicator labelled BATT shows the status of the battery.

The indicator labelled PROC indicates the current controller mode, green when the controller is in RUN mode and red when there is a problem.

The Allen-Bradley 1785-L80B is a PLC-5 series programmable logic controller (PLC).

It is part of the Enhanced PLC 5 series, which features, among other things, 100.000 words of embedded memory.

capable of holding up to 3.072 I/Os in any combination or 3.072 inputs and 3.072 outputs when operated in complementary mode.

The 1785-L80B is designed with multiple communication interfaces that can be used to communicate with different automation devices simultaneously.

It has four (4) DH/Remote I/Os (adapters or scanners) labelled CH1A, CH1B; CH2A and CH2B;.

One (1) configurable serial port for RS-232 and RS-422A electrical standards supporting the DF1 protocol, and two (2) programming terminals.