Re: 55 HELIAL LOOPS

["Jeff Duke" <jeff_d@embarqmail.com>]

Rick Walker said:

> I'm just trying to figure out what adapter to use.  Any suggestions?

Maybe this?

"Multiple message frame adaptor apparatus for loop communication system
Document Type and Number:
United States Patent 4042780


Abstract:
A serial data communication loop system includes single input-output 
controllers and/or dual message transmission with a novel adaptor unit for 
converting from a single to dual message frame and/or from a dual to 
single 
message frame. The message frames are multiple bit binary coded signals. 
The 
adaptor unit includes first and second converting sections, the first 
converting from a single input to dual output message frames and the 
second 
from a pair of identical messages to a single message output. The first 
section includes an amplifier connected to a polarity and level sensor and 
to a time delay which activates a disable timer to the amplifier and a 
strobe timer to operate a pair of transmitters to transmit the dual 
message 
frames. The second section includes a pair of receivers connected to a 
logic 
selector in combination with individual monitors which encode the status 
at 
the receivers to normally transmit from one receiver and automatically 
change to the second if the first fails. The adaptor may connect the input 
and output ports of a controller to a pair of parallel transmission 
trunks, 
automatically switch between main and back-up loop controllers connected 
in 
either a single or multiple trunk system, and provide an individual or 
group 
remote unit with message continuity if an individual or group loop is 
broken."

I think I saw one on Ebay...
Happy Birthday Rick!

Jeff