Installation guide

Estimating Network Performance
890 USE 100 00
95
Abbreviations
TTT
(n)
Token Transmission Time (for node n)
TRT Token Rotation Time
NDOL
(n)
Node Drop Out Latency (for node n)
TN
(n)
Response Time, Normal (for node n)
TA
(n)
Response Time, Abnormal (for node n)
Calculations
TTT
(n)
= (Token Pass Time: .530 + Specific Output Time: .530 +.001(Qty of Nodes
Communicated * Qty of Registers * 16))
TTT
(2)
= (.530 + .530 + .001(9 * 2 * 16)) = 1.348 ms
TTT
(3...11)
= (.530 + .530 + .001(1 * 2 * 16)) = 1.092 ms
TRT = TTT
(2)
+ 9(TTT
(3...11)
) = 11.18 ms
Normal Response Time (minimum):
TN
(9)
= (1 scan node 9) + TTT
(9) +
(1 scan node 2) + TTT
(2)
= 10 +
1.092 + 10 + 1.348 = 22.44 ms
TN
(11)
= same as node 9
Normal Response Time (maximum):
TN
(9)
= (1 scan node 9) + 2(TRT) + (2 scans node 2)
= 10 + 2(11.18) + 20
= 52.36 ms
TN
(11)
= same as node 9
Node 10 drops out, causing the following latencies:
NDOL
(9)
= 80 + 4(2) + (91) + 5(11) = 96 ms
NDOL
(11)
= NDOL
(9)
+ 11.18 = 107.18 ms
The dropout would create these abnormal minimum response times:
TA
(9)
= 22.44 + 96 = 118.44 ms
TA
(11)
= 22.44 + 107.18 = 129.62 ms
The dropout would create these abnormal maximum response times:
TA
(9)
= 52.36 + 96 = 148.36 ms
TA
(11)
= 52.36 + 107.18 = 159.54 ms