Installation guide

Estimating Network Performance
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The sending node A transmits its Specific Output data, containing Peer
Cop data to receiving node B. Node B receives this traffic immediately
as Specific Input data, and acts upon it during its next scan. The token
now passes through the intervening nodes before it is passed to node B.
Node B retains the token while it handles any ‘non Peer Cop’ traffic.
Before node B releases the token to the next node in the address
sequence, it sends the Peer Cop response data (as Specific Output) for
node A. Node A receives the data immediately (as Specific Input) and
handles the data during its next scan.
In this communication the elapsed time for the transaction is the time
between the data transmission from node A (when node B begins to act
on its data) and the transmission from node B (when node A begins to
act on its data). Because this actual time may vary somewhat for
subsequent communications between A and B (due to variable
token-holding times in the intervening nodes) it is convenient to
estimate the time as a ‘percent of network token rotation time’ as
expressed in the formula above.
3.15.2 Estimating Specific Input and Specific Output Times
Specific Input and Specific Output times for processing data in a node
with Peer Cop can be estimated using the following formula
(time in ms):
Specific Input/Output Time = .530 + .001(words * 16)
For example, if 200 words of data are sent:
Specific Input/Output Time = .530 + .001(200 * 16) = 3.73
3.15.3 An Example of Peer Cop Performance
Here is an example of a complete Peer Cop data transaction timing.
Consider a network that has an average token rotation time of 100 ms.
Two controllers are involved in the transaction, each with a scan time
of 20 ms. The ‘percent of token rotation time’ between the two nodes is
30%, for a time of 30 ms.
One scan time, sending controller
Specific output time, sending controller+
% of token rotation time, sending node to receiving node+
Specific input time, receiving controller+
One scan time, receiving controller+
Total
20.00
3.73
30.00
3.73
20.00
77.46 ms