Specifications

Mobility and Logistics, Traffic Solutions
Sopers Lane, Poole, Dorset, BH17 7ER
Security classification Unrestricted Page 38 of 83
Version 2 Status Released
Last Editor Harry Smyth Date 09/12/2014
Document Name Configuration Control Document No. 667/CC/45950/000
Copyright © Mobility 2014. All Rights Reserved. Mobility is a division of Siemens Plc
3.13 Serial I/O Cards
The Serial Input/Output (I/O) Kits do not form part of the Outercase selected from Table 2
and therefore should be ordered separately. Two types of I/O cards, remote from the CPU
Card, are available one with 4 outputs/16 inputs and one with 16 outputs/16 inputs. Four I/O
cards can fit in the ST950. Figure 26 sets out the stencil indications on the Terminal Panel,
which aids position optimisation.
Figure 26 – Serial I/O Card
The I/O cards communicate with the CPU card via the RJ45 Cable/Cat5 connector, as a
serial link. The serial link communication protocol relies on addressing techniques to ensure
the appropriate information is delivered to the intended component. This means that the
order in which the components are connected to the serial link is not imperative to
successful communications. However, to maintain consistency of build the sequence of
connections set out in Table 2 should be used.
As stated above, once connected into the serial link, the CPU card indentifies the I/O by the
appropriate address. The address is set on the I/O card, shown Figure 26. Controller special
instructions will provide details on assigned inputs and outputs.
Figure 13, 15 and 27 illustrate the mutual optimisation that must be carried out when
allocating space to both I/O card and Loop Termination Cards.
Serial Link
OUT
Serial Link
IN
Serial I/O
Address
Switch
Inputs Inputs
Outputs