Appendix C C.1 Basic Network Layout
Multi-drop RS-485 implies that there are two main wires in a segment.
The connected systems tap from these two lines with so called drop
cables. Thus all connections are parallel and connecting or discon-
necting of a node doesn’t affect the network as a whole. Since
ADAM-5000 systems use the RS-485 standard and an ASCII-based
commands set, they can connect and communicate with all ASCII-
based computers and terminals. The basic layouts that can be used for
an RS-485 network are:
Daisychain
The last module of a segment is a repeater. It is directly connected to
the main-wires thereby ending the first segment and starting the next
segment. Up to 32 addressable systems can be daisychained . This
limitation is a physical one. When using more systems per segment the
IC driver current rapidly decreases, causing communication errors. In
total, the network can hold up to 256 addressable systems. The
limitation on this number is the two-character hexadecimal address
code that can address 256 combinations. The ADAM converter,
ADAM repeaters and the host computer are non addressable units
and therefore are not included in these numbers.
Figure C-1 Daisychaining
ADAM-5000 C-3