Installation guide

86 Estimating Network Performance
890 USE 100 00
The following steps can be used to calculate the data response time for
an MSTR, and the acquisition time for global data.
1. Find the average token rotation time
Apply the formula from Section 3.12:
TR = (2.08 + 0.016 * DMW ) * DMP + (0.19 + 0.016 * GDW ) * GDN + 0.53 * N
DMW = (50 + 100 + 75 + 100 + 75 + 75) / 6 = 79 words
DMP = (1 + 20/500 + 1 + 1 + 1 + 1) = 5.04 paths
GDW = (16 + 32) / 2 = 24 words
GDN = (1 + 1) = 2 nodes
N = 6 nodes
TR = (2.08 + 0.016*79) * 5.04 + (0.19 + 0.016 * 24) * 2 + 0.53 * 6 = 21.18 ms
2. Calculate the MSTR response time
If all units have a scan time of 20 ms, then:
Average response time 1 token rotation time 21.18 ms
1 scan time of the requesting unit 20 ms
1/2 scan time of the responding unit 10 ms
Total 51.18 ms
Worst case response time 2 token rotation times 42.36 ms
2 scan time of the requesting unit 40 ms
1 scan time of the responding unit 20 ms
Total 102.36 ms