Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 12 Page 29 of 265
Each I/O card draws a maximum of 150mA and each Backplane Controller draws a maximum of
50mA. The total combination of I/O cards and Backplane Controller Cards must not draw more than
1300mA (700mA if IRM/IMU fitted and powered from 24V DC).
The maximum total number of I/O cards and Backplane controller cards in a system cannot exceed
15.
The addition of an SDE/SA card has no impact on the above tables.
Number Of
Backplanes
Required
Maximum
Number Of
I/O Cards
Maximum
Number Of
Loops
Maximum
Number Of
Inputs
Maximum
Number Of
Outputs
0 4 0 96 64
1 4 16 96 64
2 4 32 96 64
3 3 48 72 48
4 3 64 72 48
5 3 80 72 48
6 2 96 48 32
7 2 112 48 32
8 2 128 48 32
9 1 144 24 16
10 1 160 24 16
11 1 176 24 16
12 0 192 0 0
13 0 208 0 0
14 0 224 0 0
Table 2 – I/O Card and Detector Backplanes (ST900) (with IRM/IMU)
If an IRM/IMU Card is fitted and powered
from the +24V DC Supply, then the power
available for the I/O Cards and Backplanes
is reduced.