Communication Address; Multiaddress Communication - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

13.4.4 Communication address

In IEBus, each equipment is assigned to a specific 12-bit communication address. The communication
address is consisted of:
Higher 4 bits:group number (identify which group the equipment belongs to)
Lower 8 bits:unit number (identify each equipment in one group)

13.4.5 Multiaddress communication

In normal communication mode, the communication is performed on a one-to-one basis, i.e. only one
master and one slave. In contrast, multiaddress communication allows the master transmitting data to
more than one slave. As more than one slave exist in the IEBus, none of them returns an acknowledge sig-
nal in the communication.
The multiaddress bit is used to select either multiaddress communication or normal communication. For
detail description, refer to (6) transfer protocol.
Multiaddress communication has the following two modes:
• Group multiaddress communication
Communicating with equipments having the same group number as specifying in higher 4 bits of the
communication address.
• Broadcasting communication
Communicating with all equipments, regardless of the value of the group number
The slave address specified in slave address field is used to identify either group multiaddress or
broadcasting communication. For detail description, refer to section Section 13.4.6, "Transfer protocol".
MB90580 Series
13.4 IEBus Communication Protocol
Chapter 13: IE Bus 165