1785-L20E (ALLEN BRADLEY)

The PLC-5 processors are single-slot modules that are placed into the left-most slot of a 1771 I/O chassis. They are available in a range of I/O, memory, and communication capability. PLC-5 processors have ports configurable for either a Data Highway Plus messaging communication link or a Universal Remote I/O link. As a Universal Remote I/O port, it can be configured as either an I/O scanner port or an I/O adapter port. As an I/O scanner port, it monitors and controls the I/O on the link by communicating with the I/O adapters for those I/O. As an adapter port, it communicates only with the I/O scanner port on the link, passing a maximum of one I/O rack of input and output data between the two to provide distributed processing. All PLC-5 processors have Data Highway Plus and RS-232-C/422-A/423-A communication ports. In addition to these ports, each Ethernet PLC-5 processor has an Ethernet communication port, and each ControlNet PLC-5 processor has a ControlNet communication port. Although each Ethernet PLC-5 processor has on-board Ethernet ports; additional Ethernet ports can be added to any PLC-5 processor system with a 1785-ENET Ethernet Interface Module. PLC-5 processors do not have an on-board DeviceNet port. A DeviceNet port can be added to the system with a 1771-SDN scanner module.