VMIVME-5567-000

The Control Memory Xchange (CMX) module provides deterministic sharing of data among PLCs and other computing devices on a high-speed fiber optic network, using reflective memory technology. A reflective memory network can contain up to 256 nodes. Each node in the network can be any reflective memory device that is compatible with the 5565 family. When data is written to one node, all nodes on the network are automatically updated with the new data.

Each node in the reflective memory network is connected in a daisy-chained loop using fiber optic cables. The transmitter of the first node is tied to the receiver of the second. The transmitter of the second node is tied to the receiver of the third node, and so on, until the loop is completed back at the receiver of the first node. The figure on page 3 shows an example of a six-node reflective memory network.

A PACSystems RX7i main rack supports a maximum of four Memory Xchange modules.

The IC698CMX016 is a Control Memory Xchange module from the GE Fanuc RX7i Series. IC698CMX016 is a communication module used for the PACSystems RX7i programmable controllers. The PACSystems RX7i Controller functions to port applications from one hardware environment to another. The communication modules that are easily installed in these modules accessorise the distribution of input-output and control. An array of configurations and protocols are supported by these communication modules. One such module is the IC698CMX016 that is a Control Memory Xchange Module.

The IC698CMX016 facilitates the transfer of information between devices and PLCs. This transmission is carried out on a network of 2.12 gigabaud fibre optic wires. This network can host 256 nodes that are all congruous with 5565 devices. The network uses a reflective memory technology. These nodes are connected to one another forming a daisy loop pattern so that the receiver of each node is connected to the transmitter. This connectivity ensures that any change in status communicated to one node is relayed without delay to all the other nodes.

This control memory Xchange module has an effective data rate of 2.12 gigabaud in addition to 16 megabytes of reflective memory to store and process data. The IC698CMX016 has data a transfer rate that varies from 6.2 megabytes per second to 3.2 megabytes per second, depending on the density of redundant information. The module’s access time varies between 400 nanoseconds and 200 nanoseconds. The IC698CMX016 is installed using a 62.5-micron core LC type connector. The IC698CMX016 hosts 5-volt buses that require a minimum current of 1.2 amperes to function.