the mvi69-dh485 module acts as a gateway between the dh485 network and the allen-bradley"s compactlogix backplane. the data transfer from the compactlogix processor is asynchronous from the actions on the dh485 network. a 4000-word register space in the module is used to exchange data between the processor and the dh485 network.

• the module has a common interface file (cif) with 244 words that can be accessed by remote dh485 nodes
• read and write commands can be sent associated to the following file types: status, bit, timer, counter, control, integer, float, and cif
• user-definable module memory usage
• two ports emulate the dh485 devices (peer-to-peer) with distinct node addresses
• all configuration information contained in a single, user-defined text file
• compactlogix backplane interface
• all module-related data is contained in an internal database
• ability to add or remove nodes without disruption of the network
• baud rates: 9600 or 19200 baud

the mvi69-dh485 module can be used in any application where dh485 network connectivity is required with the compactlogix platform. compatible devices on a dh485 network include:

• slc 5/03
• slc 5/05 (rs-232 channel)
• 1769 - bas

the mvi69-dh485 module actively issues dh485 commands to other nodes on the dh485 network. one hundred user-defined commands are supported by the module on each port. the compactlogix processor can be programmed to control the activity on the port by actively enabling or disabling each command directly from the ladder logic.

the module also accepts dh485 commands from an attached dh485 master unit (e.g., slc 5/03 processor ladder logic msg instruction). the module permits a remote master to interact with all data contained in the module. this data can be derived from other dh485 slave devices on the network through a master port or from the compactlogix processor.