1747-6.22, Backup Scanner User Manual

A-192 Specifications
Publication 1747-6.22
Adapter #2 (1771-ASB module):
• starting logical rack 2, logical group 0
• 2 logical groups (1/4 logical rack)
• one 64 word BT write/read module
Adapter #3 (1771-ASB module):
• starting logical rack 2, logical group 2
• 2 logical groups (1/4 logical rack)
• one 32 word BT write/read module
1. Use the throughput formula to calculate the maximum
throughput of the 1747-ASB module.
Tdm-bt = 2Tps + 2TRIO + 2Tbtx + Tadp + TSNo-bt + TSNi + Tid + Tod Tps = 25.0 ms, which is from the APS reference manual (assume
for example)
TRIO = The total RIO scan time (ms)
Tbtx = Additional time due to sending any BT data on the RIO
link
Tadp = Two 1747-ASB module backplane scan times (calculated
from ASB
manual) = 2(4.5) = 9.0 ms
TSNo-bt = 22.0 ms from the table on page B-13, TSNo with
Block Transfers
(Normal Mode). There are 3 logical racks configured.
TSNi = 5.0 ms
Tid = 10.0 ms, which is from I/O module instruction sheets
Tod = 1.0 ms, which is from I/O module instruction sheets
Tdm-bt = 2(25.0) + 2TRIO + 2Tbtx + 9.0 + 22.0 + 5.0 + 10.0 + 1.0
2. Calculate the total RIO scan time (TRIO ). Locate the baud rate
(115.2K) and adapter size which is found in the table on page B-
4. Multiply the RIO scan times listed under the 115.2K heading
by the number of each different type of rack that you have. Add
those number together.
TRIO = Tadapter1 + Tadapter2 + Tadapter3
TRIO = 1(5.5) + 1(4.0) + 2(3.5)
TRIO = 16.5 ms