GE 90-70 manual Genius I/O, Local I/O, Cable Connections

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Genius I/O

The redundant portion of the system is based on Genius I/O. A system using standard Series 90-70 racks can have multiple Genius I/O bus networks. A system using the ½ slot redundant racks may have only one bus in the CPU rack. Any Genius device can be placed on the bus (Genius blocks, Field Control, Remote I/O Scanner, VersaMax I/O, etc.). The Genius devices are under control of the active unit in the Redundancy system. The Genius Bus Controller in the Primary Unit has a Serial Bus Address of 31; the Genius Bus Controller in the Secondary Unit has a Serial Bus Address of 30. Data from Serial Bus Address 31 is the preferred data when data is being sent from both units to devices on the Genius bus.

Local I/O

Local I/O can be included in the overall PLC system; however, it is not part of the Hot Standby CPU Redundancy system. Control of Local I/O is done normally through the application program. Transfer of this data between the redundancy CPUs is optional. A failure in the Local I/O system will affect the system as described in GFK-0265, the Series 90-70 Programmable Controller Reference Manual.

Cable Connections

In an Enhanced Hot Standby CPU Redundancy system that requires expansion racks, a Bus Transmitter Module in rack 0 is connected by a parallel I/O cable to a Bus Receiver Module in the next rack. The link is continued from this Bus Receiver Module to a Bus Receiver Module in the next rack. This link is continued with a maximum of six expansion racks. The last Bus Receiver is connected via an I/O cable with built-in termination (catalog number IC697CBL803 (3 feet (0.9m)) catalog IC697CBL811 (10 feet (3m)) or IC697CBL826 (25 feet (7.5m)). The last module in the parallel I/O bus link must be a Redundancy Communications Module (RCM). This terminated I/O cable allows replacement of the RCM without interrupting the running system. If no expansion racks are used, the terminated I/O cable is connected directly from the Bus Transmitter Module to the Redundancy Communications Module.

1-6 Series 90™-70 Enhanced Hot Standby CPU Redundancy User's Guide – May 2000 GFK-1527A