Specifications

Mobility and Logistics, Traffic Solutions

Sopers Lane, Poole, Dorset, BH17 7ER

Security classification Unrestricted Page 50 of 83

Version 2 Status Released

Last Editor Harry Smyth Date 09/12/2014

Document Name Configuration Control Document No. 667/CC/45950/000

4.2.4 CPU I/O Card

The ST950 Controller can be equipped with additional Input/Output cards, remote from the

CPU card. However, the ST950 can also be equipped with a CPU I/O Card, mounted in a

daughter board arrangement on the CPU Card. Please refer to Figure 34.

Figure 34 – CPU I/O Card

The CPU I/O Card is not supplied in the Outercase chosen from Table 4. Ultimately all I/O

signals are returned to / derived from the ST950 Processor. The ST950 CPU Card, CPU I/O

card, and other components described later in this handbook (I/O cards on the termination

panel and Intelligent back planes) communicate via a GSPI serial interface. The serial

communication is carried out over Cat5e cable. The serial Link relies on addressing

techniques to ensure that the appropriate information is delivered to the correct component,

therefore the order of the connections does not have an influence on the operation of the

serial link. However, for purposes of consistency the order of connection set out in Table 5

should be used. When a component is not fitted the serial link continued onto the next

component in the sequence.

Table 5 – Serial Link Connections

Component Input Output

CPU card Serial link derived from

CPU card

RJ45 Serial Link Output

Socket

CPU I/O Card RJ45 Serial Link Input RJ45 Serial Link Output

Termination Panel Upper

I/O Card

RJ45 Serial Link Input RJ45 Serial Link Output

Termination Panel Lower

I/O Card

RJ45 Serial Link Input RJ45 Serial Link Output

First Intelligent Detector

Backplane

RJ45 Serial Link Input RJ45 Serial Link Output

Second Intelligent Detector

Backplane

RJ45 Serial Link Input RJ45 Serial Link Output