dh-485 interface with reduced data block

mvi56-dh485r

the mvi56 dh485 communication module with reduced data block allows allen-bradley controllogix i/o compatible processors to easily interface with other dh485 protocol compatible devices. compatible devices include not only rockwell automation plcs (which support the dh485 protocol) but also a wide assortment of end devices.

this version of the software uses a small i/o data area for data transfer between the module and the controllogix processor, making it ideal for controlnet or ethernet applications with the module in a remote rack.

features and benefits

the mvi56-dh485r module actively issues dh-485 commands to other nodes on the dh-485 network. one hundred user-defined commands are supported by the module on each port. the controllogix 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 dh-485 commands from an attached dh-485 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 dh-485 slave devices on the network through a master port or from the controllogix processor.

applications

the mvi56-dh485r module can be used in any application where dh-485 network connectivity is required with the controllogix platform. compatible devices on a dh-485 network include:

• slc 5/03
• slc 5/05 (rs-232 channel)
• 1746bas
• mvi56-bas

functional specifications

the mvi56-dh485r module acts as a gateway between the dh-485 network and the allen-bradley"s controllogix backplane. the data transfer from the controllogix processor is asynchronous from the actions on the dh-485 network. a 4000-word register space in the module exchanges data between the processor and the dh-485 network.

this version of the software uses a small i/o data area for data transfer between the module and the controllogix processor.

• the module has a common interface file (cif) with 244 words that can be accessed by remote dh-485 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 dh-485 devices (peer-to-peer) with distinct node addresses
• all configuration information contained in a single, user-defined text file
• controllogix 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

ordering information