The Tyco 557.202.046 CCU3/C-MXMB provides a MODBUS interface to a number of MX panels on an MXNet. CCU/IO boards may also be connected to provide general I/O devices accessed through the MODBUS interface.
Tyco 557.202.046 CCU3/C-MXMB connects to MX panels on the MXNet via a TLI-800 (TPI) interface card using RS232 (PL2 socket). It connects to MODBUS via either an RS232, RS485 (default) or RS422 connection. Another port allows up to 8 CCU/IO boards to be connected. Each CCU/IO has 8 relay outputs that can be used as inputs to the MX. These contacts are controlled via WRITE commands to the MODBUS map. Each CCU/IO also has 8 supervised inputs whose status can be read from the MODBUS map.