Black Box MDR210A-485 - Manual (Page 8)

8
hop in a different sequence) the two modules will jump to separate channels on the next
hop. Using networks, multiple module pairs can operate in the same vicinity with
minimal interference from each other. The network parameter is user-definable using the
MDR210A-485 Set-up Hop Table.
Module Address
Module Addresses provide another level of addressing among the MDR210A-485
modules. Each module in a network can be configured with a 16-bit Module Address to
establish selective communications within a network. This address is set to 65535 values
using the MDR210A-485 Set-up Hop Table command.
All modules with the same Module Address can transmit and receive data among
themselves. Any modules on a network with different Module Addresses will still detect
and listen to the data in order to maintain network synchronization. However, they will
not send the data to their serial ports if their Module Addresses do not match the Module
Addresses of the transmitter.
Data Validity
The first data packet transmitted contains all bytes that accumulated in the data buffer
while the header (see Figure 2a below) was being sent. After the first data packet is sent,
another header will be sent if data is available in the buffer. The header is followed by
another data packet. The second data packet (and all subsequent data packets) will
consist of data that accumulated in the buffer while the previous data packet and header
were being sent (see Figure 2a). The size of each data packet can vary up to 64 bytes.
This progression can be seen in Figure 2b.
Sent Data:
G roup Data into Packets:
Header Data
Packet 1
Header Data
Packet 2
Header
Collect
Data for
Packet 1
Collect Data for Packet 2
Collect Date for Packet 3